2002 4.6 hard "downshift" when coming to a stop. Are there sleeves like the 6sp?

[Corellian Corvette]

Hey everyone! Recently did a fluid and filter change on my 2002 4.6is with the ZF 5spd. Fluid looked fine, dirty as expected, and replaced with the full ZF kit and Lifeguard 5 fluid. Trans as been working great.

Today as I was coming to a stop, I noticed that it was having a pretty hard downshift as I stopped. Shifting otherwise seems fine. It went away and won't happen if I come to a stop slowly.

On my cars with the ZF 6pd, this is a classic Mechatronic Sleeve problem which was fixed pretty easily. However, on REALOEM I don't see the equivalent parts, so I'm wondering if there is hard downshift fix for the 5spd similar to the 6spd.

Thanks all!

[wpoll]

Can't help much with the ZF 5sp but if you are referring to the 2-1 slam that is commmon on the ZF 6HP26 series transimissions, a simple mechatronic sleeve replacement will rarely fix this.

The mechatronic sleeve simply seals the input connector and while they commonly leak fluid when old, the resulting low fluid level is one (of many) cause of the 2-1 slam.

The ZF 6HP26 transisison can have a 2-1 slam with a brand new mechatronic seal, new pump seal, four new "jump" seals and the correct fluid level. DAMHIK...

If the transmission you are referring to is the ZF 5HP19, there are a number of "jump" seals connecting fluid orifices in the mechatronic body to the transmission case.

[crystalworks]

Interesting that RealOEM shows an A5s540z. Googling that brings up exactly one german parts supplier that shows that as the ZF 5hp24/5hp24a. Looking that up it looks like there are no tube/jump seals for that trans.

If you are experiencing the 2-1 slam (BTDT on my 6hp26z on the 4.8is) something in your trans is not holding pressure. Most likely the solenoids or associated seals. Very rarely is that fixed with a mechatronic sleeve unless your trans had leaked enough to simply be low on fluid and topping it up after the seal replacement actually fixes the problem.

If you want to experiment (I know you just put expensive LFG5 in there), you did not state your mileage or service history, I'd put some Valvoline Maxlife multi vehicle ATF in there. Reset the trans adaptations, drive for ~30 miles, and evaluate the change. The ZF fluids are very thin and unless the transmission has been serviced every ~60,000 miles since new is too thin to hold pressures after the various internal seals and solenoids have worn. The valvoline fluid has restored full functionality to more than one of my ZF transmissions.

[Corellian Corvette]

Thanks. Yeah, it's pretty minor. I have no service history with the car (it's at 160K), but the filter was not OE so I suspect it was changed at least once in its life. Trans performance is good otherwise. Also, this only happened once, and I know you can experience shifting issues when you have electrical problems and I do need new O2 sensors (getting an actual code for it) as well as the thermostat. So I want to replace those.

I did not do an adaptations reset when I did the fluid change. It wasn't that long ago, so I may do that anyway to see what happens. I usually do that when I do the sleeves on the 6spd.

Which EXACT maxlife did you use? There appear to be a few different versions now that it's so popular it was tough to figure out which version was correct.

Thanks!

[crystalworks]

For sure, do the adaptations and sort the other stuff before trying anything else.

This is the stuff. About $18/ea at Wally World. Did a pan/filter, mechatronic sleeve, tube seals, and bridge seal on my rough shifting and 2-1 slamming 6hp26z in the 4.8. Everything is butter smooth now.

Also used it in our 6hp26x that is in the wife's 2010 E70 diesel. That one has a long story detailed in the E70 section. It got a replacement trans due to E clutch bearing failure. Before replacing the transmission, the Valvoline was the only fluid that would even get the trans into 4th gear.