AT Trans Failure
#17
Rob
2nd for the Steve built AMG tranny......I got a quote from him for a complete setup...good for 525ftlbs....pricey, but worth it!!
Considering the EXTREME abuse of torque and your full weight 928 has endured......its amazing the tranny lasted as long as it did!! It appears you might have found the weak link of the automatic 928 tranny?? (once Doc figures it out anyway)
2nd for the Steve built AMG tranny......I got a quote from him for a complete setup...good for 525ftlbs....pricey, but worth it!!
Considering the EXTREME abuse of torque and your full weight 928 has endured......its amazing the tranny lasted as long as it did!! It appears you might have found the weak link of the automatic 928 tranny?? (once Doc figures it out anyway)
#18
thx brian
TC seems fine but it's going to edge racing today just cause its out and may as well be uberized if I'm going to "cattanno-ize" the valve body/etc. edge claims 575chp is fine w/their stuff and also claim they can get more TQ and HP to the wheels... should be interesting.
TC seems fine but it's going to edge racing today just cause its out and may as well be uberized if I'm going to "cattanno-ize" the valve body/etc. edge claims 575chp is fine w/their stuff and also claim they can get more TQ and HP to the wheels... should be interesting.
#19
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This explains why I did not see you at the track !!! The old very brown 1980 was the sole 928 only had one 944 as well. Lots of nice GT3 s and Turbos however. Nice event they drafted me to be an instructor got to ride in the big V-8 Audi coupe !
#20
yep.. my favorite AX venue and the friggin thing quit right after tech inspection on sunday night. spent monday frantically trying find a trans guru that could get it done in time for the timed laps, but nobody out here can seem to spell benzo, let alone porch.
I was pretty bent, as the arch nemesis in my class was there and this was about the only venue I'd have a chance to outmuscle them and get a shot at a 1st against them. now it's just friggin parking lot/go cart stuff and they usually use me for traction at those sites . and now I'm behind them in points, grrrr.
hopefully, I can get this pig fixed fast and at least out attend them. bout my only hope at this point.
I was pretty bent, as the arch nemesis in my class was there and this was about the only venue I'd have a chance to outmuscle them and get a shot at a 1st against them. now it's just friggin parking lot/go cart stuff and they usually use me for traction at those sites . and now I'm behind them in points, grrrr.
hopefully, I can get this pig fixed fast and at least out attend them. bout my only hope at this point.
#21
Definitely curious as to the what broke Rob. I'm also wondering whether or not an S4 tranny is stronger than the 32v S tranny. I've heard that the 3sp trannies are definitely weaker, which is a shame because I would seriously consider a 3 speed retrograde for my stroker if it could be made strong enough to handle the torque.
Please share details of the post-mortem, all us A/T performance hounds are definitely awaiting the results!
If there is an advantage to going with an S4 tranny compared to the 86.5 that H has offered, there is an extra '89 tranny at the shop here owned by the RMT guys that may be available. No LSD, and it has the 2.54 gears, not ideal for the stroker but maybe you could transfer over your diff?
Please share details of the post-mortem, all us A/T performance hounds are definitely awaiting the results!
If there is an advantage to going with an S4 tranny compared to the 86.5 that H has offered, there is an extra '89 tranny at the shop here owned by the RMT guys that may be available. No LSD, and it has the 2.54 gears, not ideal for the stroker but maybe you could transfer over your diff?
#22
928 Engine Re-Re-Rebuild Specialist
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When my 85's AT tranny stopped working suddenly, the car would not move under its own power in any forward or reverse gears, but did lock while in "park". The mechanic concluded that it was the valve body after he removed everything and opened it up. I ended up getting a new unit from 928 International since the mechanic's rebuild estimate was nearly 2x the price. No "thunk" or other weird noises preceded the failure, but I had been experiencing some slipping between shifts for a few days/weeks before it failed.
#23
Definitely curious as to the what broke Rob. I'm also wondering whether or not an S4 tranny is stronger than the 32v S tranny. I've heard that the 3sp trannies are definitely weaker, which is a shame because I would seriously consider a 3 speed retrograde for my stroker if it could be made strong enough to handle the torque.
Please share details of the post-mortem, all us A/T performance hounds are definitely awaiting the results!
If there is an advantage to going with an S4 tranny compared to the 86.5 that H has offered, there is an extra '89 tranny at the shop here owned by the RMT guys that may be available. No LSD, and it has the 2.54 gears, not ideal for the stroker but maybe you could transfer over your diff?
Please share details of the post-mortem, all us A/T performance hounds are definitely awaiting the results!
If there is an advantage to going with an S4 tranny compared to the 86.5 that H has offered, there is an extra '89 tranny at the shop here owned by the RMT guys that may be available. No LSD, and it has the 2.54 gears, not ideal for the stroker but maybe you could transfer over your diff?
When my 85's AT tranny stopped working suddenly, the car would not move under its own power in any forward or reverse gears, but did lock while in "park". The mechanic concluded that it was the valve body after he removed everything and opened it up. I ended up getting a new unit from 928 International since the mechanic's rebuild estimate was nearly 2x the price. No "thunk" or other weird noises preceded the failure, but I had been experiencing some slipping between shifts for a few days/weeks before it failed.
dropped off the TC at edge racing this AM. quite a shop, that's all they do so they do seem pretty into all aspects of the TC and give a good feeling of confidence their stuff won't blow up later... $375.00 estimate and 3 day turnaround. http://www.edgeracingconverters.com/ their website
sent an email to steve c. to get this going... guess we'll see.
steve's website: http://www.mastertechtrans.com/
Last edited by 928SS; 05-13-2008 at 07:18 PM.
#24
they took it all apart and found nothing! gears all look fine, clutches still new, bearings good. no goofy stuff on the valve body!!
only thing I can think now it that it's the dang rebuilt TC (for the stall increase), although the splines looked fine. should know more on that later today when they cut it open for the edge racing upgrade.
course, since I live on the slippery slope of upgrade-itus - we'll be sending the VB out to steve anyway, and I think it'll need a rear 928 SP sway bar, since it's just sitting there begging me to replace it w/something shiney....
only thing I can think now it that it's the dang rebuilt TC (for the stall increase), although the splines looked fine. should know more on that later today when they cut it open for the edge racing upgrade.
course, since I live on the slippery slope of upgrade-itus - we'll be sending the VB out to steve anyway, and I think it'll need a rear 928 SP sway bar, since it's just sitting there begging me to replace it w/something shiney....
Last edited by 928SS; 05-14-2008 at 03:54 PM.
#25
the TC is fine. I'd HIGHLY recommend edge racing - they don't change stall by just slamming some shims in. they change the impeller angle, tighten clearences, some other magic stuff. they also claim I'll get another 10-15rwhp and tq over the unit I had in there!! guess that's an upside to all this.
sooooo - the problem MUST me in the valve body (like big dave) and the tards looking at it just couldn't figure it out. steve should be able to when he does his shift kit upgrade magic and I'll update as I find out more info...
sooooo - the problem MUST me in the valve body (like big dave) and the tards looking at it just couldn't figure it out. steve should be able to when he does his shift kit upgrade magic and I'll update as I find out more info...
#26
the TC is fine. I'd HIGHLY recommend edge racing - they don't change stall by just slamming some shims in. they change the impeller angle, tighten clearences, some other magic stuff. they also claim I'll get another 10-15rwhp and tq over the unit I had in there!! guess that's an upside to all this.
sooooo - the problem MUST me in the valve body (like big dave) and the tards looking at it just couldn't figure it out. steve should be able to when he does his shift kit upgrade magic and I'll update as I find out more info...
sooooo - the problem MUST me in the valve body (like big dave) and the tards looking at it just couldn't figure it out. steve should be able to when he does his shift kit upgrade magic and I'll update as I find out more info...
Did you send them a copy of a dyno chart and tranny gearing etc etc...so they can set the stall speed accordingly?
Ya see... i blew my supercharger belt a few weeks ago and i figured that while im in there.......
#27
yep.. they've got all the poop. they have special vane angles, impeller clearance options, for whatever suits your needs and to improve efficency. doing the sway bar and TC are nothing for the slippery slope hall of infamey. I did the stroker to fix an oil leak
also repainted my whole shark after washing it once cause it didn't look right. prolly should've just waxed it. guess that's pretty good for the slippery slope, but I think your S belt thingy to a TC might top that one
I think sterling's rear end remodel qualifies after his fender bender for sure too!
I think our credo should be, "why just fix it when you can uberize it!"
#28
too funny
yep.. they've got all the poop. they have special vane angles, impeller clearance options, for whatever suits your needs and to improve efficency. doing the sway bar and TC are nothing for the slippery slope hall of infamey. I did the stroker to fix an oil leak
also repainted my whole shark after washing it once cause it didn't look right. prolly should've just waxed it. guess that's pretty good for the slippery slope, but I think your S belt thingy to a TC might top that one
I think sterling's rear end remodel qualifies after his fender bender for sure too!
I think our credo should be, "why just fix it when you can uberize it!"
yep.. they've got all the poop. they have special vane angles, impeller clearance options, for whatever suits your needs and to improve efficency. doing the sway bar and TC are nothing for the slippery slope hall of infamey. I did the stroker to fix an oil leak
also repainted my whole shark after washing it once cause it didn't look right. prolly should've just waxed it. guess that's pretty good for the slippery slope, but I think your S belt thingy to a TC might top that one
I think sterling's rear end remodel qualifies after his fender bender for sure too!
I think our credo should be, "why just fix it when you can uberize it!"
#30
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Here's a hint: When auto transmissions grenade inside, all the resulting debris flushes through the system until lots of little pieces have caused lots of little scratches in hyrdraulic actuator and valve body bores. If you know you are going to "upgrade", consider doing it before the trans fails. It will be way cheaper and way more reliable when done. Think about buying a good used gearbox now and doing your fixes on it, and just swap it in. You'll remember where all the bolts went, you'll have minimum downtime, and you'll have a marketable used trans to resell. Plus the swap will happen at a time onvenient to you, rather than waiting for the most inconvenient time, which is what the old trans will do.