I'm having a re-manufactured engine put into my 02 SSEi that has 109,000 miles on it. We are going to keep this vehicle for at least three - five years, maybe more. We drive it approximately 15,000 miles a year. Does it make sense to put in a rebuilt tranny now while the engine is out? I'm assuming I'll have to eventually replace it or have it rebuilt (my 92 Bonne had to have its tranny rebuilt at 130,000 miels. I'm asking this question with the assumption you have to remove the engine replace the tranny. My initial thought is to take my chances and run it until it needs rebuilt.

4T65 Transmission (miles before rebuild)

If it were me, I would run with it - you may get lucky and have it last a long time.
IMO, there are usually plenty of warning signs before transmission goes completely.
If it happens you might be able to limp around while you shop/schedule repairs to minimize your down time.

as long as you take care of it, you can have it last for a long, sonoma zr2 had his last for like 29x xxx miles

We have over 165,000 miles on our car and its still going strong.

ROD

Based on what I'm reading, It seems to be a crapshoot. Because the one and only owner before I bought it was a grampa who put 55,000 miles on it driving it back and forth between NY and FL and because my wife drives it like an "old lady" (I drive her hard every so often, ..... the car that is ) I think I'm gonna pass on putting in a tranny and take my chances. Thanks for the insight.

thats surprising that you need a new motor at 109 K. My SSEi has 217,000

my parents 97 SSEi has lasted almost 190k with no issues, but I personally dont have good luck with these trans. The original trans went in this car at 100k, was rebuilt by ZZP and went again at 114k, however it was raced. I have since put in a used junkyard unit with 40k on it and have been golden since (knock on wood). I currently have about 20k on the trans since the swap.

My mom bought her '00 SSEi brand new in '00. The trans started slipping at around 170k and she had it rebuilt shortly thereafter. The car now has 217k on the clock with no trans issues on that trans. Keep in mind this car had less than 1000 miles on it when we began modding it and it has seen the track and is driven very hard. It also has raised shiftpoints and higher shift pressure and all that commanded in the PCM.

Also figure I should mention that we never even so much as dropped the tranny pan on the original tranny, so that was original fluid and all in that trans. I'm sure with a fluid/filter change regularly it probably would've lasted a bit longer.

99 SSEi #1 (my first SSEi)
Orig trans lasted 136k miles
Rebuild again at 142k miles
Been going good ever since and last I heard had 180k+ over a year ago.

98 SSE (My 3rd SSE)
Bad solenoid, but didn't repair/replace solenoid. Still going strong and I see the car on the road every day -no doubt it has over 210k miles now.

99 SSEi #2 (2nd and current SSEi)
Original trans bad at 119k -snapped input shaft)
current trans is from a 00 GTP and has 43k miles and is doing well with a Transgo Shift kit.

02 Park Avenue Ultra (Moms)
95k miles and still going strong

04 Park Avenue Ultra (Dads)
91k miles and still going strong

97 SSEi (brothers)
230k miles and has a bad 4th gear, doesn't want to go into gear until car is warmed up.

97 GTP (cousins)
265k miles and is missing 2nd gear, otherwise is doing well.

99 SSEi (sisters)
105K and it has a bad solenoid -clunks on take-offs every so-often.

98 LSS (Brothers old one)
206k miles on original trans and it shifted/operated like you'd expect a new one to.

1997 Park Avenue (was mine, then Dad'*, now Uncles)
Bought with a bad transmission at 130k'ish miles IIRC.
Replacement trans had 70k supposedly and has close to 150k now and as far as I know it hasn't given any problems since installation.