I had posted this in the bonneville attitute forum thread dealing with similar problems, although it doesn't look like anyone responded on whether this is a "real" possibility for fixing the transmission problem (maybe because it involves fixing the transmission...). I would be interested if anyone who has this transmission shudder problem gives this bulletin to the transmission shop or dealer & see what the feedback is. :?

http://www.atra-gears.com/gears/02jul/2002_07_22.pdf

On some basic level, although I think GM builds a good & solid car (clearly better quality than other domestics, in my view), I just don't understand how they can keep having these recurring problems, at relatively early mileages, on something like this. It is an obvious engineering problem, so why don't they figure it out?? I once had a Buick Regal, 1981 I think, with a turbo-hydramatic and this was the most trouble-free, smooth transmission I ever saw. That was over 20 years ago - what happened, GM??

Another couple of related questions:

(a) has anyone found (as I did) that these issues are reduced by locking out OD? and is there any downside to locking out O/D in normal city driving? (if I'm on the highway, or otherwise over say 2,500 rpms, I put it back in O/D)

(b) I'm wary of additives, but is there any ATF additive that people 'swear by' ?

Thanks.

Hey Aardvark,

I agree and disagree with you.

First, I agree that GM makes good cars. But I have had best luck with Pontiacs, they just keep going. My next car is either going to be a 2001 Bonneville or a 1999 BMW 740. I have driven both and would compare them fairly equal.

The problem with technology is that there are lots of things to go wrong. I do not know many other cars that get 31MPG on the highway. But the Bonne does due to its lock up torque converter and TCC solenoid. Some Japanese 4 bangers would love to get 31Mpg, and American 4Cyl cars like a Cavalier only get 25Mpg. That sux.

So yes, reliablity can be an issue when they keep designing new technology. The 81 Buick Hydromatic transmission is not real high tech but it works well.

I have a friend that was looking at buying a car and has been buying Japanese cars. I said that Pontiacs are great, as long as you dont mind little things going wrong. Its always something small thats a problem, but not usually anything that stops the car. They just keep on going forever.

Second, I am investigating the fact that it is a trans issue here. I dont want to admit it though, coz that means real money. I am trying to get my hands on 3 coil packs to replace those and see if it helps. But as you suggest, its probably the Torque Converter.

To answer your questions, I found that locking into D instead of OD didnt change things at all. It still does it in both positions.

I dont know about any additives. Some people swear by them, but I have never had many results. My mechanic put a "great" additive in my trans oil last change but it didnt do a thing to help this issue.

Cheers,

Andrew

Hi, Andrew, these are interesting posts. I basically agree with you re GM quality - I've driven only GM for at least the last 10 years. When I sold my 93 Bonneville recently, I test-drove a 96 BMW 850i that the dealer here had for sale for $36,000 (Cdn. - about $24,000 US). What I found was, yes, just the feeling of driving a car like that was fantastic (ie driving a car almost no-one else has really is a great feeling). But at the end of the day, hard to justify spending that much money on a 7 year old BMW where you know if anything ever goes wrong it'* $1,000+ to fix. So I bought a 96 Bonneville that has been absolutely babied by previous owner. Cost $7,000 (say $5,000 US), and that was at the dealer. I've driven that car for a month now & it seems perfect, so I'm happy.

Good luck with the transmission, let us know what happens!

Aardvark

Hi Aardvark,

Yes, I agree about the costs. I can get a 2001 Bonne SSEi for about $14k. I can get a 1999 740i for about $14K. Cool huh.

Anyway, that is probably off this topic. Thanks for the tips and I post the results of my transmission/missing/stuttering/surging issue.

Cheers,

Andrew

I had that exact same problem with my '93 SSEi.

Turned out to be the Torque Convertor trying to lock up.

But that'* just me........I also managed to bend both front axles (or C/V joints anyway) and twisted the clutches to the point where the mechanic could not understand HOW i managed to do what I did and HOW it managed to shift at all.

Got brand spankin new tranny and new axles...........
(API warranty was the greatest thing I ever bought)

Yeah those 7 series lose a lot of value like a bonnie. Can't believe a car that sold for 30 grand is worth $4k in great shape, while a GP that was prob 10k less then the bonnie in worse shape are more. 7 series can ber very nice though... But i'm a 5 series kinda guy, why i like bonnies i guess.