AT Trans Failure
05-15-2008, 02:00 PM
#31
Road Warrior
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+1 on what dr bob says! and being stranded isn't fun, although if near a bar it's not quite so bad.
course, it helps to put it back together eventually - right brendan? hehehe
BJ, re: drivability - the old TC was ok w/the stock motor w/upgraded stall of 2200rpm (vs 1500 or so stock). but it was just done w/shims, not by specing vanes, impeller and clearances like edge is doing. it came off the line like shot out of a cannon if you got on it, compared to stock. but w/the stroker it just spun like stupid slamming in 455ft lbs rwtq at 2000 rpms and it always felt kinda sloppy if you were below 2krpms or so. not a big deal putzing around on the street, but if smooth corner transitions are your goal it was kinda twitchy/took a lot of throttle control to mitigate the "hit" when throttle steering.
new unit should feel tighter/more like a stick all the way up from idle w/smoother/tighter throttle response - according to the builder. I might re-dyno to see if hp claims are real, when I get a chance. I'll do a seat o the pants update after I get to take it for a spin for ya though.
FWIW, I"ve beat my stockish (just a cheap shift kit added) AT to death on drag strips, "test runs" and doing AX stuff w/the stroker, a tight LSD & 295x18 140tw tires (fairly sticky / wide). everything looked new in there still, so I don't think you'll break many hard parts very easily unless you're putting down over 550-600rwhp/tq and flogging it hard. it's an MB unit designed for turbo diesel trucks in europe, and used in the MB 560SEC/built like only an obsessed german can do. I have broken and bent the rear drop link bars though.
as a side note - I would recommend putting in the old style Torque Tube w/the circlip to prevent TBF and shaft creeping if you're gonna be abusing things... iirc, 928SP also has a special clamp that is supposed to help resolve that issue.
course, it helps to put it back together eventually - right brendan? hehehe
BJ, re: drivability - the old TC was ok w/the stock motor w/upgraded stall of 2200rpm (vs 1500 or so stock). but it was just done w/shims, not by specing vanes, impeller and clearances like edge is doing. it came off the line like shot out of a cannon if you got on it, compared to stock. but w/the stroker it just spun like stupid slamming in 455ft lbs rwtq at 2000 rpms and it always felt kinda sloppy if you were below 2krpms or so. not a big deal putzing around on the street, but if smooth corner transitions are your goal it was kinda twitchy/took a lot of throttle control to mitigate the "hit" when throttle steering.
new unit should feel tighter/more like a stick all the way up from idle w/smoother/tighter throttle response - according to the builder. I might re-dyno to see if hp claims are real, when I get a chance. I'll do a seat o the pants update after I get to take it for a spin for ya though.
FWIW, I"ve beat my stockish (just a cheap shift kit added) AT to death on drag strips, "test runs" and doing AX stuff w/the stroker, a tight LSD & 295x18 140tw tires (fairly sticky / wide). everything looked new in there still, so I don't think you'll break many hard parts very easily unless you're putting down over 550-600rwhp/tq and flogging it hard. it's an MB unit designed for turbo diesel trucks in europe, and used in the MB 560SEC/built like only an obsessed german can do. I have broken and bent the rear drop link bars though.
as a side note - I would recommend putting in the old style Torque Tube w/the circlip to prevent TBF and shaft creeping if you're gonna be abusing things... iirc, 928SP also has a special clamp that is supposed to help resolve that issue.
05-29-2008, 05:44 PM
#32
Road Warrior
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update - valve body didn't have any obvious damage when steve saw it. but it was apart and had some shipping bumping, so a stuck valve could have come loose. no other issues in trans, so that had to be it.
steve went through it, did a through OH and inspection, added his goodies and this baby should fly again in the next week or 2.
got the TC back, looks awesome and it's now fitted w/roller bearings, HP vanes and tighter clearances, etc... got a "free" Edge Racing T shirt and stickers too. or a free TC OH w/350.00 shirt and stickers.
steve went through it, did a through OH and inspection, added his goodies and this baby should fly again in the next week or 2.
got the TC back, looks awesome and it's now fitted w/roller bearings, HP vanes and tighter clearances, etc... got a "free" Edge Racing T shirt and stickers too. or a free TC OH w/350.00 shirt and stickers.
08-11-2008, 08:41 PM
#34
Road Warrior
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update from hell: man it's hot here! and the local mechanics are pure torture!
got it back on the road around mid july. they put in another $400 worth of bands and clutch plates that "looked worn". couldn't find the used parts though. hmmmmm. then it blew oil so bad it covered the rear of the car in less than 80 miles. I took it back. was alledgedly a leaking servo seal.
got it back again a week later. still shifting at 5400 from 1st to 2nd. and it was still leaking, this time from the rear seal. took it back again.
got it back for the 3rd time on 1st weekend of August. still short shifting. I chkd the cable and it had a 1/4" of slack in it. I adjusted it, and drove it about 2 miles, seemed to shift much better, super quick and sure. stall seemed a bit lower, but it was over 100 deg at 3400 feet, so w/hot tires it seemed to just hook up and launch vs just going sideways, seemed to shift VERY quick and firm, but not harsh. was quite smooth when not on it. thought I was going to have some fun this summer after all. visions of driving it again danced in my head.
then on the way up the driveway it quit with a loud pop and hit the revlimiter while shifting from 1st to 2nd. wouldn't go forward, just skipped and jerked, will easiliy over rev if not careful. reverse is fine. I nursed it into my garage, and next day had a flatbed come and get it. hell can be so... evil!
it sat for 8 days at R&S, waiting for the owner to return from vacation. then he called me, "sorry but we are not going to be able to get it the way you want it. so come get it and we'll give you a refund". I must be a real demanding ***** for asking that it shift per the manual at redline more or less, not leak and actually be able to move on it's own in 2 directions. strange thing is - I NEVER pushed them or was rude or a jerk in anyway. all I ever said was, "these things happen. just take your time and lets get this done right". my gut says this is for the best, for obvious reasons.
so I picked it up w/my car hauler. (guess I won't be selling that for a while, lol) they did promise a refund, but the boss wasn't there. just keeps getting better and better, lol. at least it's not leaking anymore, lol. why am I laughing? so I don't beat those tards to death w/a phucking halfshaft, lol.
thx to doc brown (to the rescue yet again), I found a local shop that only does benzo / 928 trannies. new guy also thinks its was just the valve body w/a stuck valve, "they stick all the time, no big deal to fix - don't even have to pull the trans". lol. keep laughing rob, just keep laughing. it's only a visit to hell, not there for good - yet...
new guy (trans miester in orange, ca) thinks it could just be a servo that commonly breaks as the culprit for the newest symptom.
apparently, benz has 4 versions of it for the 928 trans. the latest has a special teflon coating that's the ultimate cure. if you are OH'ing one of these, check into that part. it's a must have.
on the upside - the new trans guy claims it could be fixed in an hour, assuming the servo is now the only issue. and steve c. has been a great reference/sounding board throughout it all. thx again steve!!
guess we'll see what happens tomorrow when I take it to the new guy. if I see a pitchfork in his shop I'm going to the nearest church to wash my shark in holy water.
got it back on the road around mid july. they put in another $400 worth of bands and clutch plates that "looked worn". couldn't find the used parts though. hmmmmm. then it blew oil so bad it covered the rear of the car in less than 80 miles. I took it back. was alledgedly a leaking servo seal.
got it back again a week later. still shifting at 5400 from 1st to 2nd. and it was still leaking, this time from the rear seal. took it back again.
got it back for the 3rd time on 1st weekend of August. still short shifting. I chkd the cable and it had a 1/4" of slack in it. I adjusted it, and drove it about 2 miles, seemed to shift much better, super quick and sure. stall seemed a bit lower, but it was over 100 deg at 3400 feet, so w/hot tires it seemed to just hook up and launch vs just going sideways, seemed to shift VERY quick and firm, but not harsh. was quite smooth when not on it. thought I was going to have some fun this summer after all. visions of driving it again danced in my head.
then on the way up the driveway it quit with a loud pop and hit the revlimiter while shifting from 1st to 2nd. wouldn't go forward, just skipped and jerked, will easiliy over rev if not careful. reverse is fine. I nursed it into my garage, and next day had a flatbed come and get it. hell can be so... evil!
it sat for 8 days at R&S, waiting for the owner to return from vacation. then he called me, "sorry but we are not going to be able to get it the way you want it. so come get it and we'll give you a refund". I must be a real demanding ***** for asking that it shift per the manual at redline more or less, not leak and actually be able to move on it's own in 2 directions. strange thing is - I NEVER pushed them or was rude or a jerk in anyway. all I ever said was, "these things happen. just take your time and lets get this done right". my gut says this is for the best, for obvious reasons.
so I picked it up w/my car hauler. (guess I won't be selling that for a while, lol) they did promise a refund, but the boss wasn't there. just keeps getting better and better, lol. at least it's not leaking anymore, lol. why am I laughing? so I don't beat those tards to death w/a phucking halfshaft, lol.
thx to doc brown (to the rescue yet again), I found a local shop that only does benzo / 928 trannies. new guy also thinks its was just the valve body w/a stuck valve, "they stick all the time, no big deal to fix - don't even have to pull the trans". lol. keep laughing rob, just keep laughing. it's only a visit to hell, not there for good - yet...
new guy (trans miester in orange, ca) thinks it could just be a servo that commonly breaks as the culprit for the newest symptom.
apparently, benz has 4 versions of it for the 928 trans. the latest has a special teflon coating that's the ultimate cure. if you are OH'ing one of these, check into that part. it's a must have.
on the upside - the new trans guy claims it could be fixed in an hour, assuming the servo is now the only issue. and steve c. has been a great reference/sounding board throughout it all. thx again steve!!
guess we'll see what happens tomorrow when I take it to the new guy. if I see a pitchfork in his shop I'm going to the nearest church to wash my shark in holy water.
08-11-2008, 10:48 PM
#35
I have yet to find a transmission shop that doesn't play these games Rob.
Good luck. That "Four versions" thing is quite interesting.
Good luck. That "Four versions" thing is quite interesting.
08-11-2008, 11:02 PM
#36
Road Warrior
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I'll do an update on the new guy... iirc, greg and 928 intl use him, so that's a big plus. I probably should've started w/him, but was too lazy to bring it down... oops.
worst case, the way adam's thread is going, I'll be able to do it myself by dec, hahaha
worst case, the way adam's thread is going, I'll be able to do it myself by dec, hahaha
08-11-2008, 11:07 PM
#37
Three Wheelin'
Why not pack up and send the transmission to Steve to fix it right? By the end, it seems like you'd be ahead from both a dollars and time perspective...?
08-11-2008, 11:37 PM
#38
Banned
I had the same issues with a transmission shop here in Sarasota, Florida, Barbic's trasmission repair was recommended by a reputable Porsche repair shop here in town, which had 928s sitting in the shop. The first time I went there a couple years ago he gave my car back to me with a "rebuilt" tranny and it was ****, slipped when changing into 2 gear, didn't have 4th gear, he gave it back to me saying he couldn't do the job even though they "had done plenty of 928s" bs. The tranny finally dropped out completely and I got ahold of a used euro tranny. I brought it to them with and after taking my old tranny out and looking at the new used tranny which was from an 86 euro I believe with 60k on it, they said it couldn't be done and gave my car back to me in pieces. I vowed to prove him wrong and began my quest to get the job done, I started purchasing all the parts to do the conversion. Wether it be a stroke of luck or fate, Crazy Mike saw my car outside my old job and inquired as to wether or not it was for sale. My buddy got his number and long story short we finally got her installed and she is running great. Keep your head up it will all be worth it.
08-12-2008, 01:08 AM
#39
Road Warrior
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he's an option for sure. but if the new guy can just R&R the servo, it seems like the path of least resistance at this point. if it has to come out again, steve is back in the game unless the local guy really impresses me somehow....
I'm keeping my AAA card handy no matter what though
08-12-2008, 06:50 PM
#41
Road Warrior
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IT LIVES!! was just the servo thing like ted suspected. had it running within an hour! didn't get to test it too much, but on the test rack it pulled all 4 gears just fine. drive test seemed fine too...
total cost: $116.00 !! this guy knows the benzo trans intimately. just watching him was night and day vs the R&S guys. he went straight to it, told me everything he was doing, and could tell what was coming out before he even started.
for west coast stuff I wouldn't hesitate to use this guy. he's not a big mod type guy like steve, but knows the OEM stuff very well. also races circle track, so he's a gearhead through and through.
transmeister. ted reich 714 532 1871 836 w. angus ave, orange, ca... one of a rare breed of 928 capable guys that make the 928 resource short list, imo...
total cost: $116.00 !! this guy knows the benzo trans intimately. just watching him was night and day vs the R&S guys. he went straight to it, told me everything he was doing, and could tell what was coming out before he even started.
for west coast stuff I wouldn't hesitate to use this guy. he's not a big mod type guy like steve, but knows the OEM stuff very well. also races circle track, so he's a gearhead through and through.
transmeister. ted reich 714 532 1871 836 w. angus ave, orange, ca... one of a rare breed of 928 capable guys that make the 928 resource short list, imo...
08-15-2008, 01:41 PM
#42
Road Warrior
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well, it died again! spewed oil all over the rear and lost all gears & reverse. presumabley due to fluid loss.
took it back to ted. ted found the breather hose was cracked at the resovour connection and most likely was the culprit this time. many thx to R&S, one more time - NOT! can't imagine why anyone would put on a 20 yr old cracked hose, but I suppose thats another good reason it's not ever going there again.
filter was clogged w/melted fluid and the pan bottom was pretty ugly too. drained all fluid. prolly from the servo adventure and the latest fiasco combined. I'd like to think R&S at least had cleaned the pan/used a fresh filter. maybe.
apparently there is an upgraded filter for these that has a weighted slide that will close 1 end and open the other as the car brakes and accelerates. it's used on all the newer benzos. works great on performance cars to keep the pump from running dry/sucking air, cost is about $75.00. I had one slapped on.
there are also 2 resevours available - a large and small. larger is better cause it's not as sensitive to minor fluid losses. not any easier to access though. does have a nice factory heat shield. have to use a different pan, but they swap easily. had that done too. ted threw it in for free! cool dude!!
car still was dead though after a fluid flush and refill. apparently the valve body most likely either got clogged up w/burnt fluid or it didn't get the original sticking mystery valve replaced and it's misbehaving again. looks like we went full circle on this one now. only took 2.5 months so far.
but ted is going to have it done by today, hopefully.
when he does do an OH it takes about 6 hrs to rebuild a trans if it's not a total disaster (not counting R&R). pretty fast, but that's all he does. he replaces all the stuff he's replacing on mine now as part of the standard OH, and does clutches, plates, internal seals, and a few other internal high failure parts w/upgraded benzo stuff as a precaution. seems pretty thorough.
another $300.00 for everything. pretty reasonable, imo. guess we'll see. if it's still dead, then it's OH time. at least this time I think it'll get done right.
took it back to ted. ted found the breather hose was cracked at the resovour connection and most likely was the culprit this time. many thx to R&S, one more time - NOT! can't imagine why anyone would put on a 20 yr old cracked hose, but I suppose thats another good reason it's not ever going there again.
filter was clogged w/melted fluid and the pan bottom was pretty ugly too. drained all fluid. prolly from the servo adventure and the latest fiasco combined. I'd like to think R&S at least had cleaned the pan/used a fresh filter. maybe.
apparently there is an upgraded filter for these that has a weighted slide that will close 1 end and open the other as the car brakes and accelerates. it's used on all the newer benzos. works great on performance cars to keep the pump from running dry/sucking air, cost is about $75.00. I had one slapped on.
there are also 2 resevours available - a large and small. larger is better cause it's not as sensitive to minor fluid losses. not any easier to access though. does have a nice factory heat shield. have to use a different pan, but they swap easily. had that done too. ted threw it in for free! cool dude!!
car still was dead though after a fluid flush and refill. apparently the valve body most likely either got clogged up w/burnt fluid or it didn't get the original sticking mystery valve replaced and it's misbehaving again. looks like we went full circle on this one now. only took 2.5 months so far.
but ted is going to have it done by today, hopefully.
when he does do an OH it takes about 6 hrs to rebuild a trans if it's not a total disaster (not counting R&R). pretty fast, but that's all he does. he replaces all the stuff he's replacing on mine now as part of the standard OH, and does clutches, plates, internal seals, and a few other internal high failure parts w/upgraded benzo stuff as a precaution. seems pretty thorough.
another $300.00 for everything. pretty reasonable, imo. guess we'll see. if it's still dead, then it's OH time. at least this time I think it'll get done right.
08-15-2008, 02:25 PM
#45
Three Wheelin'
So what do you estimate is the range for a rebuild for an average joe, including R&R?
After R&R the transmission, do you have to readjust the flex plate or does the torque tube mount in such a way that the rear doesn't affect the front?
After R&R the transmission, do you have to readjust the flex plate or does the torque tube mount in such a way that the rear doesn't affect the front?