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What I thought was chugging turned out to be the transmission going out. Now my question is what FWD vehicles can I get a transmission from that'll work in my car? This happened on the day I was supposed to leave for California. Please be prudent in helping me out. Thank you.

You need a 4T65EHD that will have to some out of a supercharged car. You will want a 2003+ unit as they have the heat treated splines for 4th gear that won't strip out. See this website for more information http://tripleedgeperformance.com

Pretty much you have to have a 4T65 that is made for the Bonneville. There is structural webbing that uses the rear trans mount. You must have this or you will crack the rear of the trans.

You need a 2003 Trans because of the Valve body. It is unique....OR you can remove your valve body and channel plate from your current trans and use it in any 2000+ Trans. Where are you located

If you crawl underneath, look up at where the passenger side axle comes in, there will be a sheetmetal tag in that area on the back of the trans. It will have a 3 digit alpha-numeric code, denoting the specific transmission. You'll need to find a trans that matches that code.

Found one at a local wrecking yard. Same year with supercharger. Going to have to go on blind faith here.

Will the 2005 Grand Prix transmission that has a Series III L67 engine work in my Bonneville?

only if you change the Valve body and Channel plate.

as a drop in replacement, no

2003 SSEi wrote:only if you change the Valve body and Channel plate.

as a drop in replacement, no

Will that trans have the mount holes for the back trans mount?

crash93ssei wrote:

2003 SSEi wrote:only if you change the Valve body and Channel plate.

as a drop in replacement, no

Will that trans have the mount holes for the back trans mount?

it depends, some do and some don't....its crazy, I have see W bodies with and with out that webbing on the back of the trans, and there is no rhyme or reason, nor it is year specific

here is what im talking about

Webbing


no webbing

Found one in a 1998 Grand Prix GTP. will that work in my car?

Look to see if it has the webbing near the rear trans mount like in pat's picture. If it doesn't, then it won't work for a direct swap.

Well it does. And the fluid is nice and bright red. But I know that don't mean it's good.

nope wont work, unless you swap the valve body and channel plate (insert broken record here)....plus I think 98 had an External range switch, and your 03 has an Internal range switch....

so....no

Is the case just too weak without the webbing to handle the torque? I would think it could handle torque fine with all the topswaps.

Zeik75 wrote:Is the case just too weak without the webbing to handle the torque? I would think it could handle torque fine with all the topswaps.

the case is not designed for the incorrect mount. There was a member that tried the non webbed version and cracked the rear of the case with a stock car when it was put in drive

Can the transmission be extracted with out removing the subframe?

Let's go back to square one here...
You say it is surging under light-moderate load?
What are the problems that are happening with the transmission?

lets get right down to it HERE.... my father is a certified master tech and knows this transmission is a descendant of the 125C. I told him I heard what sounded like a dry bearing and that I thought it was the supercharger going bad. When he heard this, he told me something in the final drive went bad. I am believing it to be the planetary gears that are in the final drive. Could some one please answer the transmission removal question or direct me to a place in this forum on how to remove it? I am pressed for time here.

Not to be rude, but being a certified master tech really don't mean much. Not at all trying to discredit him and his work, but we have seen dozens of times over the years where a certified master mechanic said something and it turned out not to be. It doesn't matter what transmission this one descended from, this isn't that same old transmission so things will not necessarily be the same between them. Take the time and explain what was done to nail the transmission as the issue here, more then just someone heard an explanation from you and said the trans was the problem. People here are trying to help you out and make sure that what you spend your hard earned money on is actually going to fix the problem.

STILL didn't answer my question on how to remove the transmission which was clearly asked twice in this thread. I was cordial in my request as well. Again… can this transmission be removed with out the sub frame being removed or can someone please redirect me on the forum to where there are instructions in how to do it?