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Rebuilt Trans trouble ???

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Just had the trans rebuilt on my 93 500sel. The car seems to drive ok under normal acceleration, but if I floor pedal at about 50 mph the car stalls(as if you over accelerated in park)instead of taking off like it used to.It seems like the engine is going too fast for the trans, or is being governed prematurely. I'm taking the car back this week, but does anyone have an idea what might be wrong? Thanks for the help !
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W140 S class, E31 850Ci, XC90 Exec AWD geartronic
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My bet is on the torque convertor

It could be incorrect vacuum pressures...or torque co...


My bet is on the torque convertor

It could be incorrect vacuum pressures...or torque convertor problems. Did you have the torque convertor renewed at the same time as the rebuild?
 

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1993 500sel
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Discussion Starter · #3 ·
TRANS REPAIRS

They said they replaced the torque convertor. I took it to another shop that worked on mercedes, they told me I had no 3rd gear. I'm going to take it to an actual trans shop to get a road test and evaluation. Do you have any other possible opinions on this? Thank you for responding.
 

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My transmission was skipping 1st gear after mine was rebuilt. The mechanic noticed this be...

My transmission was skipping 1st gear after mine was rebuilt. The mechanic noticed this before returning the car, and the tranny was sent away for rebuild #2. The cause of it missing the gear was down to a hairline fracture on that gear and the gear was replaced.

Are you sure that the car is missing 3rd gear? I would start the car on a clear road and count the gear changes all the way upto 4 (your car has a 4 speed), Then do the same but whilst accelerating hard without using kickdown.

The flaring (reving) between the gears under pressure is usually down to the torque convertor or incorrect vacuum pressures.

Auto transmissions are quite complex. I would recommend you get a professional diagnosis.
 

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Discussion Starter · #5 ·
I'll try the road test

Thanks again. I'll try to count the shifts. I'm just repeating what the second mechanic told me. It seems as if it hits all gears to me, it's just when I floor the gas pedal the engine seems moves faster than the trans wants to take it. I still have to take it to a reliable trans shop for what I feel is a proper diagnosis. Also a side note.....My a/c main line has been cut. It is a clean slash, do you think it possible it may have been damaged in the repair of my trans. Its up front near the trans cooling lines and is protected from any possible road damage w/the undercovering.
 

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Discussion Starter · #6 ·
still trouble....

I took the car back. They made some adjustments. The car still stalls upon hard accelaration. The trans seems to operate ok under normal accelaration...Here is a scenerio......Riding on the xpressway say 55 mph, A car is in my way, I want to blow past him, I floor the gas,car begins to take off but then redlines, ...now comes the stall or hesitation if you will. When I let up on the gas the car resumes gaining speed , but if doesn't give me that "turbo boost" performance I used to get before the trans was rebuilt. The shop says its fine and says it is probably engine related. I don't believe this, but I have an appointment w/the dealer 7/30/03. Please....anyone reading this at anytime, please give me some insight. It seems as if it is an adjustment or some little thing that only an experienced MB tech would pickup on. I'll let you know what MB dealer says....Thanks
 

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Re: still trouble....

car begins to take off but then redlines, ...now comes the stall or hesitation if you will. When I let up on the gas the car resumes gaining speedYour text here

Ok, now is it just holding the gear too long and hitting the rev limiter? Bouncing off redline? When you let off the gas does it feel like the gear is engaging, and where do the rpms drop to when you let off a little? You could be just hitting the rev limiter from a tranny problem holding the gear too long, it could be coming out of gear when you floor it, hitting redline, and then when you back off it slips into gear, or it could just be an ignition thing like a bad coil. What happens when you floor it from low speed and hit redline? Same feeling? Hesitation?
 

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Re: still trouble....

I took the car back. They made some adjustments. The car still stalls upon hard accelaration. The trans seems to operate ok under normal accelaration...Here is a scenerio......Riding on the xpressway say 55 mph, A car is in my way, I want to blow past him, I floor the gas,car begins to take off but then redlines, ...now comes the stall or hesitation if you will. When I let up on the gas the car resumes gaining speed , but if doesn't give me that "turbo boost" performance I used to get before the trans was rebuilt. The shop says its fine and says it is probably engine related. I don't believe this, but I have an appointment w/the dealer 7/30/03. Please....anyone reading this at anytime, please give me some insight. It seems as if it is an adjustment or some little thing that only an experienced MB tech would pickup on. I'll let you know what MB dealer says....Thanks
these exact same symptoms as mine was showing prior to rebuild. The proper terminology for this is called slipping or flaring. Stalling is when the engine cuts outs.

I think they are lying to you. They probabily just adjusted the vacuum pressures and passed the car back to you not wanting to re-strip the gearbox. MB will tell you that you need a new transmission. They do not preform transmission repairs. Get them to write saying that you need a new transmission for insurance purposes - as I did (MB will do this for free thinking they will be getting the work) then go back to the tranny shop and present them with the diagnosis. If they wont play ball, threaten them with legal action for shoddy workmanship
 

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Discussion Starter · #9 ·
trans flaring

Thanks for the response. When I floor the gas, sometimes the trans will shift if the shifts beats the rpm to the redline. If it doesn't the car flares until I release the gas. Then the car resumes speed. I'm not sure at what rpm it resumes, I just know that it used to take off when I accelerated hard. It never stalled or flared I think is the correct terminolgy. It's hard to explain , but the effect I get can be duplicated if one would press the gas pedal, while in park until the car redlines. The car then flares to protect the engine from over accelation. ( sounds like enga, enga, enga )until you release the gas.This is exactly what happens when I am driving and accelarate hard. Instead of performance, I get left in the dirt because the car flared. I hope that helps you to help me. Thanks again....[xx(]
 

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Discussion Starter · #10 ·
At low speed accelaration it seems to hit the gears right althoughit gets very close to ...

At low speed accelaration it seems to hit the gears right althoughit gets very close to redlining before the shift.
 

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Discussion Starter · #11 ·
trans lying

I think they are lying and just plain lazy. They just don't want to do what is necessary to correctly repair this trans.I still have leaks and because they blame the engine i have an appointment at the dealer for a tune up and diagnosis of the trans and engine.I'm sure Mercedes will try to get their share of money out of me, but I am compiling info for almost certain legal action. PS... Instead of replacing the trans pan because they stripped the screw, they keep trying to repair it.....They even managed to break my trans dipstick....Whats that about??? Does anyone know how many times you have to give them to correct the same problems under warranty?
 

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Re: At low speed accelaration it seems to hit the gears right althoughit gets very close to

At low speed accelaration it seems to hit the gears right althoughit gets very close to redlining before the shift.

Tipstas, this is the EXACT problem my transmission had. It was because of this, I had it rebuilt. I drove it like this for some time (long story) and eventually the car gave up shifting into 4th gear 70% of the time.

MB diagnosed a new tranny after trying to adjust vacuum pressures.
 

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Discussion Starter · #13 ·
trans trouble

Thanks again Gill. I think my trans will need to be rebuilt , after this rebuild. Or new better yet... I take the car to MB tonight. Hopefully tomorrow they will at least give me a good diagnosis. I'll inform you on the extent of my repairs and continued "dollar diet"[xx(]
 

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Discussion Starter · #14 ·
back from the shop

I took the car to the dealer. They performed a tune-up. They said all the computer and valve settings were correct, but there was an internal trans problem.Itook the car back to the trans shop and told them what the dealer said. They kept the car a week. They said they replaced the valve body w/a remanufactared one. The car seems to shift ok now although I haven't put it on the expressway yet.I did notice that in park when i rev the engine, It redlines @ 5500 instead of 6000 which is the actual beginning of the redline
 

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Re: back from the shop

I took the car to the dealer. They performed a tune-up. They said all the computer and valve settings were correct, but there was an internal trans problem.Itook the car back to the trans shop and told them what the dealer said. They kept the car a week. They said they replaced the valve body w/a remanufactared one. The car seems to shift ok now although I haven't put it on the expressway yet.I did notice that in park when i rev the engine, It redlines @ 5500 instead of 6000 which is the actual beginning of the redline
Excellent, at last your tranny is shifting as it should [:D]
 
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