Spec X5 Overland Build

[Henn28]

The pups and I escaped Iowa between storms late Tuesday afternoon. Had to cut our trip short, but the weather was atrocious. We had a short break on Tuesday afternoon where the snow mostly stopped and the wind hand not picket up yet to a raging howl, as forecast. I will say that the Quaife was an expensive upgrade, but is definitely not on that list of the upgrades I've done to the X5 and struggled to justify afterwards. Just having one differential that isn't open on that X5 made a huge difference in how it handled in some really terrible conditions. 95% of the time it was seemless in how it moved torque to the wheel that had traction, but occasionally I did find myself tapping the brakes to fool it into thinking it had a little traction on the slipping side. Its not a true LSD in this respect so if you have zero traction on one side, it will still try to send all the torque there. Tapping the brakes (or the DSC working) will force the worm gear magic within the diff to work and transfer torque to the other side.

Happily we found lots of quail for a change and flushed a lot of very, very wily late-season phez. The highlight of Monday was getting locked out of the X5 by my 9 year old dog who I left in the car to rest. Unfortunately I opted not to load a crate in the X5 this year and I foolishly left the keys in the center console because we were in a hurry. Few other sinking feelings match the realization that you are on the outside of your X5 and your pissed off 82 lb bird dog is in the inside and won't let you in, and that you are soaking wet, its 25 degrees out and the wind is blowing to 30 mph in a remote Iowa corn field...and its getting dark in an hour. I can imagine him banging around the inside of the X5 trying to figure out why he got left in the car while that other dog he lives with didn't, and stepped on the door lock. There are no bad dogs, just stupid owners and I proved that. Fortunately my buddy talked me out of breaking the small window on the rear door so we got dry clothes at his house which was somewhat close and some tools. Long story short: we wedged the front passenger door open at the top/left jamb with wooden shims (he's a carpenter) and ended up snaking some very heavy gauge wire with a hook bent into it and lifting the handle a bit. I then held this arrangement while he snaked another piece with a loop on it and got it around the handle and yanked once to unlock. Like I tell my kids, life is about the stories you are able to bore your grandkids with someday...so make them good.

1950 round trip miles and the X5 was a beast. Nothing like 20 degree weather, ice and 40 mph winds to make me anxious about the strange noises the car was making.


Some were just because it was so cold and the car was covered in ice most of the time. Doors frozen shut, ice in the seals, wheel wells and undercarriage caked, etc. Some need attention though, at some point.

I'm still fighting a slow speed knock over bumps from the front right. The new monoball tension struts are pretty amazing, but neither those nor the new Bilstein struts fixed that problem. Looks like lower control arms are next as I've read that those can cause a slow speed knock. I have a new set of ball joints (tension strut ends), but that will wait until I need some bloody knuckles as the first hex bolt I tried to get out stripped immediately. They did feel pretty tight though when I replaced the tension struts.

The car developed a slight but very distinct whine from 30 to 40 mph only. Very much like alternator whine through the stereo but only after a cold start and it would stop when the brakes were tapped (drive side versus coast side of the pinion/ring gear maybe?). I'm pretty convinced that this is from the new diff, and must either be an output bearing(s) or the backlash. The backlash was at the very upper end of what Quaife said was acceptable, but I didn't want to pull the pinion. I suppose it could be the pinion bearings too, ebay donor differentials being what they are. I've read that its tough to put too much pre-load on output bearings, but I suppose it could be coming from there too. At any rate, I'm going to drain it next week and look at the magnetic plug. If it is relatively clean with no chunks, I'm going to close it up and live with it for a while. My 1993 grand Cherokee has had massive backlash issues and bearing whine from the rear diff for 15 years and it still makes it to the X5 rescue scene every time. The good news is that I've got the OE diff than came out of my X5 in my shop so I can break that down at my convenience and learn how to rebuild a pinion, set preload, etc.

I will say though that the ride with the Turner monoball tension struts is noticeably tighter and the car corners really well. The ride is a bit stiffer too. Nothing uncomfortable, but noticeable. This is likely in combo with upping the pressure on the Geolanders to 35 PSI in a fruitless quest for slightly better MPG, and the new Bilstein B4s up front too. I'm a fan of the mono-ball and will remain so if they they last longer than 2 years. I'll go with the turner monoball lower control arms to match and install them in the next few weeks. I'm going with complete struts and arms so I can hang on to the 2 year old ones that came out. If the monoballs fail too soon, I'll be disappointed for sure but I can try the poly bushings guys like and put them into these (now spare) struts/arms.

Finally, I definitely need a new tie-rod boots as mine are rock hard and the left one has shattered. They are the OE tie-rods so I think I'll replace them (inners and outers). Have never done tie-rods so any advice is welcome. I know I need a huge crows-foot, or maybe a special tool to take the inner one out, and a special pliers to install the inner boot clamps? Can this job be done without removing the stiffener plate? Also, if I'm careful and measure the old tie rods/count threads, can I do the job and not need an alignment afterwards?

[workingonit]

Originally Posted by Henn28

...The car developed a slight but very distinct whine from 30 to 40 mph only. Very much like alternator whine through the stereo but only after a cold start and it would stop when the brakes were tapped (drive side versus coast side of the pinion/ring gear maybe?). I'm pretty convinced that this is from the new diff, and must either be an output bearing(s) or the backlash. The backlash was at the very upper end of what Quaife said was acceptable, but I didn't want to pull the pinion. I suppose it could be the pinion bearings too, ebay donor differentials being what they are. I've read that its tough to put too much pre-load on output bearings, but I suppose it could be coming from there too. At any rate, I'm going to drain it next week and look at the magnetic plug. If it is relatively clean with no chunks, I'm going to close it up and live with it for a while. My 1993 grand Cherokee has had massive backlash issues and bearing whine from the rear diff for 15 years and it still makes it to the X5 rescue scene every time. The good news is that I've got the OE diff than came out of my X5 in my shop so I can break that down at my convenience and learn how to rebuild a pinion, set preload, etc....

If yours isn't too loud, and only whining on coast, then I wouldn't be too worried. I've had 3 whining differentials on my old Chevelle drag racing car, caused by setting them up where the "drive side" pattern was perfect, the "coast side" not so much. But, my diffs weren't the new-fangled Quaife, so I might be comparing apples to oranges.

The first one (a 3.73 Richmond gearset, with Eaton LSD, to be used on the car while it was still street/strip capable) was set up that way by a professional shop, that dealt only in drag-race diffs and axles. They said that the sound (when coasting) was normal for their diffs. I learned to like it, and that diff was still working fine (in another car, after I sold the whole rear end) 20 years later.

The second differential was set up by me and my master mechanic friend, at his home shop. It was a 4.56 set, again with an Eaton posi. Also, again, the diff whined on coast, but the Eaton was too weak (started slipping), when after I blew my first 427 engine while racing, we built the second (441 c.i., 14:1 compression, solid roller cam) BBC engine for it. That second BBC was too strong for the posi unit.

At that point, the Chevelle was race-only, so we installed a Moser (or Strange) full-spool differential (both axles are locked together), 4.88 gears, C-clip eliminators, and Moser 33-spline axles. It whined on coast, also, but that harmonized well with the gear-drive (instead of a chain drive for the camshaft) in the engine. It was a head turner when returning through the pits, with the engine loping and the camshaft geardrive whining (and 2.5" open headers) all making a great sound...everyone always looked.

Here's a post on https://www.thirdgen.org/forums/tran...ons-drivetrain that gives some good info about gear whine



Also, heres a chart with gear teeth patterns, as a reference

[Henn28]

Great info, thank you Workingonit...I think I used that same gear mesh pattern picture when checking mine. the front is quite good, I think, but the rear is shifted to the heel a bit.

Two notes: no whine at all today when I drove the X5 to the store here at home. Its 65 degrees though so I wonder if the gears in the diff don't like 25 degree oil? Also, I've been running Amsoil Severe Gear and went to order two new bags of it (much easier to squeeze into the diffs from underneath), but I noticed that it has friction modifiers in it. Not sure how I missed this.
The quaife isn't an LSD so friction modifiers are not called for. I'll grab some red line from my local AutoZone tomorrow when I change the fluid.

Also, that gear driven top end must have been a monster! I watched something where Gorden Murray was talking about the Cosworth V12 in his T50 car. The Cosworth guy being interviewed said that for RPM above 10k (I think) you need a gear driven valve train. That motor spins to over 12k. crazy.

[workingonit]

What weight gear oil are you using? In the last iteration of my Chevelle, I was using a 90/140 (or thicker?) gear oil with some additives, that my friend (who built a lot of drag cars back then) had formulated for him, and kept a 55-gal drum in his storage room.

It may have been Royal Purple, which he seemed to have a special relationship with, as he could get their packaged oil products at ridiculously low prices. I would stop by their local distributor sometimes, on my way home from work, to pick up some more for him, as it was only 20 miles out-of my way but he'd have to drive 160 miles round-trip to pick up (I'd take it to him the next trip out to his shop, 50+ miles from my house).

Anyway, it was made for N.Texas drag racing, usually from March 1-Nov. 1, so it would thin out nicely during warm/hot weather; but, in cooler weather, I'd have to drive extended runs in the pits or return roads, pre-race, to get it warmed up (couldn't just warm the engine up static, as the tranny and diff needed to be at operating temp, too).

Since you're in S.Louisiana, think about using a thicker weight gear oil than you normally would, as your normal ambient temp is even higher than here in DFW. But, watch out for polar vortexes if you plan to drive without a gradual warm-up first.

About my car's top end: it was a heavy car (3800-4000 lbs) with a moderate stall speed convertor (4500 rpm) and a high starting gear ratio (1.76:1) in the trans-braked Powerglide, two-speed transmission. Thus, it was slow off the line, compared to most of the cars in my class, usually stripped-down Rustangs (65-68, or 5.0 bodies with Chevy BBC'S in them), other 64-69 General Motors A-bodied Camaros, or 62-65 lightweight Exner-styled full-size (or later B-bodied Road Runners & GTX's) Mopars, so that's why I went to 4.88 gears, for more oomph off the line.

It definitely made some noise, because I'd hit the 1/4-mile at 7200+ rpms, which is a bit high for most BBCs, but we used the strongest parts available so it'd hang together (I set the rev limiter at 7600 rpm...most other BBCs had theirs set nearer 6800 rpms). And my un-tubbed wheelwells, and class rules, made me run 28" diameter slicks, so top end speed was limited there too. My best was 10.75 secs @ 127 mph on an ill-prepared track (oiled-down in a prior race). I'm sure the sound level reached was pretty high, and contributed greatly to my ever-present tinnitus, that came a few years later.

[Henn28]

Originally Posted by workingonit

What weight gear oil are you using? In the last iteration of my Chevelle, I was using a 90/140 (or thicker?) gear oil with some additives, that my friend (who built a lot of drag cars back then) had formulated for him, and kept a 55-gal drum in his storage room.

It may have been Royal Purple, which he seemed to have a special relationship with, as he could get their packaged oil products at ridiculously low prices. I would stop by their local distributor sometimes, on my way home from work, to pick up some more for him, as it was only 20 miles out-of my way but he'd have to drive 160 miles round-trip to pick up (I'd take it to him the next trip out to his shop, 50+ miles from my house).

Anyway, it was made for N.Texas drag racing, usually from March 1-Nov. 1, so it would thin out nicely during warm/hot weather; but, in cooler weather, I'd have to drive extended runs in the pits or return roads, pre-race, to get it warmed up (couldn't just warm the engine up static, as the tranny and diff needed to be at operating temp, too).

Since you're in S.Louisiana, think about using a thicker weight gear oil than you normally would, as your normal ambient temp is even higher than here in DFW. But, watch out for polar vortexes if you plan to drive without a gradual warm-up first.

About my car's top end: it was a heavy car (3800-4000 lbs) with a moderate stall speed convertor (4500 rpm) and a high starting gear ratio (1.76:1) in the trans-braked Powerglide, two-speed transmission. Thus, it was slow off the line, compared to most of the cars in my class, usually stripped-down Rustangs (65-68, or 5.0 bodies with Chevy BBC'S in them), other 64-69 General Motors A-bodied Camaros, or 62-65 lightweight Exner-styled full-size (or later B-bodied Road Runners & GTX's) Mopars, so that's why I went to 4.88 gears, for more oomph off the line.

It definitely made some noise, because I'd hit the 1/4-mile at 7200+ rpms, which is a bit high for most BBCs, but we used the strongest parts available so it'd hang together (I set the rev limiter at 7600 rpm...most other BBCs had theirs set nearer 6800 rpms). And my un-tubbed wheelwells, and class rules, made me run 28" diameter slicks, so top end speed was limited there too. My best was 10.75 secs @ 127 mph on an ill-prepared track (oiled-down in a prior race). I'm sure the sound level reached was pretty high, and contributed greatly to my ever-present tinnitus, that came a few years later.

Sounds like fantastic machines you built. Building for the track seems like it must require a much higher level of detail and execution. It’s amazing how much work we put into the cars. And money. Competition, and then winning takes it to a completely different level. I really appreciate a guy like Paul Newman, who had enough money, brand, and interest and energy to start a winning race career while having another career. I need to hit the lottery.

I’m back in Louisiana and zero whine yesterday in 65 degree temps. This am it was 43 and I got the subtle whine again between 25 and 30ish. I realized though that I’ve been using Amsoil severe gear 75w 90 all these years, and it’s in the Quaife diff right now. The stuff has LSD modifier in it which the Quaife doesn’t call for. Togher to find synthetic without friction modifier in it at the local stores, so I ordered 3 liters of LiquidMoly from FCP and will change out both diffs next week. I’d be surprised if that had anything to do with the whine, but maybe. I’ll try this first, then maybe a heavier weight if it doesn’t help.

Next up is my transfer case. I can feel what I believe to be lot of slack in the chain, which isn’t surprising at 166k miles. With the driveshaft disconnected it’s very easy to feel slack in the transfer case as it’s the only thing connected. I think the chain jumping off is a show-stopper in the non-xdrive cars? Cobra sells new ones at $2400 each, which is prohibitive, so I’m thinking of the eBay donor route again. That way I can take my time and get it right, swapping it in when it’s done. Thanks in advance to the guys who have done this rebuild and posted lessons learned.

[Bdc101]

Yeah, if the chain breaks or otherwise jumps off the teeth you will be stranded similar to having the front driveshaft hop out. I'm curious about this as well, I have some fluid to put in the transfer case as in 7.5 years I've never opened that up. I am only at 135k miles but it's the preventative maintenance that will keep these cars on the road, rather than reactive maintenance.

[Henn28]

Originally Posted by Bdc101

Yeah, if the chain breaks or otherwise jumps off the teeth you will be stranded similar to having the front driveshaft hop out. I'm curious about this as well, I have some fluid to put in the transfer case as in 7.5 years I've never opened that up. I am only at 135k miles but it's the preventative maintenance that will keep these cars on the road, rather than reactive maintenance.

I second that, for sure. If I've got some part of the car apart for some reason, I'll absolutely research and consider replacing or rebuilding, etc. any other component or system that is easier to get to due to the work I'm doing.

Regarding the xfer case. I did some quick research today and found there are two that can fit the 2002 pre-xDrive? I think the early cars all came with the NV125 (mine did) but per RealOEM that was superseded by the LWX 500 apparently? The input shaft is different so that needs to be swapped out with the NV125 input shaft.

I wonder what the difference is internally? Cobra even sells new LWX 500 models with the NV125 input shaft installed. I'd be happy to source one of these to rebuild if it was stronger internally, or otherwise a better piece of gear.

Edit...
A little more sluthing turned up this from Cobra:
https://cobratransmission.blogspot.c...-transfer.html

And some YouTube videos on replacing chains. Looks like the LWX is an easier piece to break down, with no c clips, etc.

[Bmwe5320023.0]

My rear diff whines as well. X5 2002 3.0
I was wondering what that loud whine was, it scared me. Very similar to "alternator whine" that I once had with a new audio system..
I figure it must be the diff, unless I did something wrong with the transfer case rebuild. However I was pretty confident with the transfer case job, not so much with the diff 4.10.
On top of adding the LSD locking plate from racingdiff, I also used 2 diffs to make one lol! And never checked the gear teeth pattern. So who knows, maybe the diff will die soon. The whine comes and goes, but it's there on acceleration, not just coasting. Not sure if the rear diff goes, can it damage the transfer case.

In terms of NV125, I did a full rebuild, chain, all bearings and seals. I'll be posting a video in a couple of weeks, it's pretty long and it going through editing now. Hopefully it will be helpful to whoever wants to rebuild their TC.

[Henn28]

Originally Posted by Bmwe5320023.0

My rear diff whines as well. X5 2002 3.0
I was wondering what that loud whine was, it scared me. Very similar to "alternator whine" that I once had with a new audio system..
I figure it must be the diff, unless I did something wrong with the transfer case rebuild. However I was pretty confident with the transfer case job, not so much with the diff 4.10.
On top of adding the LSD locking plate from racingdiff, I also used 2 diffs to make one lol! And never checked the gear teeth pattern. So who knows, maybe the diff will die soon. The whine comes and goes, but it's there on acceleration, not just coasting. Not sure if the rear diff goes, can it damage the transfer case.

In terms of NV125, I did a full rebuild, chain, all bearings and seals. I'll be posting a video in a couple of weeks, it's pretty long and it going through editing now. Hopefully it will be helpful to whoever wants to rebuild their TC.

I don't think the actual diff carrier and gears will let go...but then I don't know how they interact with the LSD set up in yours. You've also got a spare diff to work with now too, I think? I suspect, if we screwed up our builds, the output bearings will slowly wear prematurely and begin to make themselves known with a loud humming noise. From what I gather from Workingonit, and other things I've read, the pinion/ring set up doesn't have to be perfect for the diff to last a long time. The diff in my 1993 grand cherokee has been humming and backlashing like crazy when selecting park and reverse for the last 15 years.

My whiny sound hasn't come back since getting back from Iowa. Of course it hasn't been nearly as cold in Louisiana as it was up there. Who knows, it could have been something else. I did change out the diff oil one last time with non-lsd synthetic from MollyLube and the stuff that came out had some silver tint to it after a few thousand miles. There was a small bit of muddy magnetic goop on the magnetic plug too, but not a lot. I suspect that I pre-loaded the output bearings a bit too much perhaps, if anything. Hopefully they just needed a good break-in.

[Henn28]

Still avoiding the CV boot job, so I takled another, more cosmetic job today on the X5. My CSF oil cooler was mounted on a bracket a friend made for me, and screwed into the front bumper in two spots where the bumper cover bolts into the metal bumper. Not the strongest set-up, and no protection for the cooler. So I was happy to see that after 22 years, ECS Tuning is making some overland-oriented parts for the E53, including a light bar. So I grabbed one with the thought of using it for a better cooler mount, and a place to put some KC driving lights.

I elected to install it upside down as this position made for a better cooler mounting position, and offers some protection for the cooler. The CSF cooler is exceptionally heavy duty, and has survived one "gentle" rear-end accident, courtesy of my daughter, but I'd like a bit more. The bar simply bolts into the tow hook points and is 1" powder coated steel tubing. They make a tow hook that I've got on order which is longer and will engage the thread, and hold the bar on.



I cut some simple brackets from 3/16th steel and measured/drilled the hole to mount the brackets to the pre-drilled light attach brackets on the ECS Tuning bar, and mount the cooler to my home made brackets.


After that it was just a matter of bolting it up with some black stainless fasteners, cutting holes in the tow point covers and putting it all together.



Much more secure solution that I'm pretty happy with. I've got some light clamps to pop on and some 4" KC classic Halogen driving lights to install and wire up when then arrive. ECS is making a switch set-up for the ash tray which I will use, and modify two of the positions for the USB plugs I've got snaked into the ash tray from my Kenwood head unit currently.