Looking for some information on if this is possible or what needs to be done. I have the following:

2000 Bonnville SE complete car I want the trans out of - 3.05 differential
2000 SSEi that has no 4th gear that I want to put the trans into - 2.93 differential


1) Has anyone done a straight swap like this with success even with the different diff gearing not screwing up the shift points too badly (only a 4% difference)?

2) Will this be a direct bolt in regarding the CV shafts and any wiring harness, etc.?

3) If the diff gearing is a problem, would I just be able to swap the 3.05 diff in the donor trans with the current 2.93 diff in the bad trans? If this is easy, i think its my ideal situation since id rather have the higher gears for economy.

Thanks

Just swapping over the SSEi'* -HD differential, cover, and output shaft is not enough; the drive/driven sprocket ratio is not the same in the -HD vs. non-HD trans. Those sprockets would need swapping over, too...UNLESS you have access to a tuner, in which case you can adjust for the difference in sprocket ratio.

(Apart from the parts I mentioned above, those -HD and non-HD 4T65E'* are identical)

But first, question: you say you have no OD in your current trans; is it good otherwise?
It is quite possible that the 4th clutch hub is simply worn out. VERY common issue on 4T65E prior to 2003 (when GM went to a hardened hub). That'* a fix that costs about $100 in parts, and is really not hard DIY with the trans out of the car.

ok - Thanks. To answer your question - the trans is functioning besides OD and I assume its the hub, as the car downshifted with a huge thud and never went back in OD. However the trans shift rough sometimes and slips a bit others. I have the donor trans which was rebuilt by a local performance shop 50,000 miles ago. I figure why try and fix a notoriously problematic trans with a 105,000 miles on it?

Can you confirm what ouput shaft you are referring to? (I apologize, but I generally only do work like this on my rear drive cars and feel like i have a language barrier) In which the output shaft would be connecting to the driveshaft; in a FWD trans, do the CV shafts connect to the output shaft?

Your plan makes sense to me, if your current trans seems to be going out on you and the replacement is so recently rebuilt.

Output shaft is the shaft that runs inside the length of the trans, linking the differential (on the passenger'* side) to the driver'* side axle. The -HD output shaft is a tiny bit longer than the non-HD, due to the diffy'* being different.
(Swapping output shaft/diffy/diffy cover not difficult, though you must be careful not to break the plastic lube dam the shaft runs through.)

Are you planning to swap the drive/driven sprockets from your current trans to the new trans, or are you going to get your PCM tuned/reprogrammed to the "hybridized" gearing?
(Swapping sprockets is considerably more difficult and requires opening the case, but is far from impossible; will cost some $20 to $30 in new gaskets, plus another $50 or so if you decide to upgrade that 4th clutch hub...assuming that wasn't already done on the rebuild)

If swapping sprockets, this (very lengthy) thread may help you:
BonnevillePRO.com • View topic - Rebuilding a 4T65E-HD
(I can also get you a .pdf copy of the literature if you PM me an email address)

If planning a PCM reprogram, either talk to a vendor (Intense, ZZP), or let us know where you are located and maybe someone with a tuner is near you.

Thanks for the info. I would really appreciate the literature. You can send it to rossi1369@hotmail.com. (I cant send a PM to you yet).

I was thinking about swapping sprockets over getting the thing programed, depending on difficulty. I am in Sparta, NJ though if anyone is close by with a tuner.

I guess my next question though is, Can the non-hd trans be bolted up and have the pcm programed for the 3.05 gears? This would seem like the simplest solution.

I'll get that trans literature to you Monday.

I would not use the non-HD 3.05 differential with the SSEi. The -HD diffy is beefier for a reason.

If you swap over only the -HD diffy/OP shaft to the SE trans, you will wind up with 3.29 gears; that can be tuned for, but is not what you want it sounds like.

If you are bound and determined to use the 3.05 trans as-is, I'm sure it can be tuned for. But, if you use the non-HD diffy, you will need to get a 2000+ non-HD passenger'* side CV axle (the different diffy'* take different CV axles).

Whatever you decide, if you change from 2.93 gearing, run your idea past zzperformance.com or intense-racing.com (PCM vendors), or look up BillBoost37 or mcgrath on this board (or on bonnevillepro.com) for details of what needs done in the PCM.

Just wanted to say thanks Agrazela.....I completed the swap last weekend and everything is working perfectly. I ended up swapping the sprockets and differential and it really wasnt that difficult especially with the manual you provided, it was all a huge help.

The 4th clutch hub was bad in the ssei trans, and the rebuilt trans had a post '03 hub in it already. So nice to have OD again.....