BMW E53 3.0i -- Front&Rear Differential Change + Other various suspension components

[Happy]

Originally Posted by RocketyMan

I have to say, wow! 1st gear is now totally more usable. I can get up to about 20mph before upshifting into 2nd gear. As a side effect, the car is less "jerky" when on and off load in 1st gear.

Now when I cruise around town I can easily do it in 4th gear at 40ish mph and it is just less high strung. The fun part is at highway speed, 70 mph is an easy 3000 rpms! Right where I wanted it! I've been apprehensive about updating this post in terms of reporting mileage because I have an emissions related fault code I'm trying to solve now. It popped up halfway through my 150 mile trip I took it on. :/

In addition, I'm going to order a new front drive shaft. I'm gonna lose sleep on the splines becoming looser in the T-case as I just checked it last night.

I am glad it worked out for you! It’s always nice to achieve results that you were hoping for. For cruising on the highway at 70 mph, you nailed it. It should definitely provide additional mpg’s.

[andrewwynn]

Measure your current drive prop length, I think BMW made two lengths and the short one doesn't engage very far into the TC. Eventually when the mounts wear out enough the spline will pull out enough to slip.

If the spline engages even 3/8" that is not going to happen. There is a myth the spline can somehow wear down and skip without pulling out. That absolutely does not happen. It has to pull out to slip.

Some people have put spacers on the guibo to attempt to get a little farther into the TC and somebody makes a two part front prop so you can install the longer style without unbolting the TC or dif.

I wonder if the shaft has a label that could have survived to know the model number.

[Clavurion]

Originally Posted by andrewwynn

Measure your current drive prop length, I think BMW made two lengths and the short one doesn't engage very far into the TC. Eventually when the mounts wear out enough the spline will pull out enough to slip.

If the spline engages even 3/8" that is not going to happen. There is a myth the spline can somehow wear down and skip without pulling out. That absolutely does not happen. It has to pull out to slip.

Some people have put spacers on the guibo to attempt to get a little farther into the TC and somebody makes a two part front prop so you can install the longer style without unbolting the TC or dif.

I wonder if the shaft has a label that could have survived to know the model number.

How does the front propeller pull out when engine-gearbox-transfer case-front propeller-front diff is one package?

[andrewwynn]

Looking at the TIS it says you remove the guibo and there's supposed to be enough room to pull the prop out of the TC.

From what I've read: "notsomuch" I read that people have to mess with front subframe mounts or whatever the dif is attached to in order to make room. My theory of the shorter prop shaft is to make assembly possible with engine and dif already in the car.

[andrewwynn]

Everbuilt front drive shaft Repair kit with 1" extended splines For Bmw x5 front drive shaft, 2000-2003 Ref part # 26207508629 https://www.amazon.com/dp/B07T5WTFZT..._-giWEb7K4J1PK

A kit to replace the spline end of the prop shaft and add an inch.

[Clavurion]

Originally Posted by andrewwynn

Looking at the TIS it says you remove the guibo and there's supposed to be enough room to pull the prop out of the TC.

From what I've read: "notsomuch" I read that people have to mess with front subframe mounts or whatever the dif is attached to in order to make room. My theory of the shorter prop shaft is to make assembly possible with engine and dif already in the car.

I was questioning your theory that the splines wear out because the front propeller pulls out. Not just that they simply wear out because contact surface is so short.

[crystalworks]

I've always thought a contributing factor was that the AC evaporator drains are right above the driveshaft where it meets the Xfer case. Couple that with not a lot of engagement, especially as the mounts age, and the shaft spines grind up the corrosion until they finally give way. That's always been my understanding of it but I have a late model so take that for what it's worth. Just reading and no personal experience.

[andrewwynn]

If the seal doesn't do its job and keep the water out, corrosion shortening the mouth is just another way to say the shaft pulls out.
I haven't seen the situation first hand to try to determine with more certainly but from what I've seen in photos and description, it seems to be a design defect where BMW didn’t have enough spline insertion. The seal prevents the spline from going in farther even if you try to use spacer on the guibo so really the options are either the spline shaft pulls away when the dif pulls forward (or motor/trans/TC push back), or the spline inside the TC moves backward.

[andrewwynn]

Originally Posted by Clavurion

How does the front propeller pull out when engine-gearbox-transfer case-front propeller-front diff is one package?

I see now we were talking about different things. I thought you were asking how to do the service now how can it happen during self destruct mode.

I think that the combination of the motor/TC mounts and the sub frame / differential mounts wear enough that during some maneuver such as a hard left turn the dif moves far enough from the TC to pull the prop out of the TC.

[Clavurion]

Originally Posted by andrewwynn

I see now we were talking about different things. I thought you were asking how to do the service now how can it happen during self destruct mode.

I think that the combination of the motor/TC mounts and the sub frame / differential mounts wear enough that during some maneuver such as a hard left turn the dif moves far enough from the TC to pull the prop out of the TC.

Like I previously said engine-gearbox-transfer case-front propeller-front diff is one solid package with everything bolted together. So they won't move in relation to the other.