Transmission rebuild....or just a clutch or shifter issue???

Transmission rebuild....or just a clutch or shifter issue???


NE Florida
1983 CJ7 258 T5
I wanted to finally take the Jeep for a drive to see how it behaves and what other issues we may need to address. I wasn't sure about the condition of the trans fluid, so i decided to do a drain and fill on the T5. I did alot of research on which fluid to use and came up with many answers. In the end I decided to go with 2 quarts of Pennzoil Synchromesh that was recommended by several people who had great results, one of which was a guy who rebuilt many T5s as a business.

I have driven it previously, but only for about a half mile. Each time, I was able to from 1st through 4th at the most, given the short distance. This time I was able to drive it for a few miles. Shifting was pretty easy, but I suspected a worn throw out bearing based on a familiar noise I was hearing. On the way back, I was stopped at a light and when I started going forward in 1st, I heard a loud bang and it seemed to come out of gear.

Pulled over and was able to get it in 1st a few times and start to go forward, but it would either make a bang noise or grind. I was able to get it back home by starting out from 2nd gear. When I had it back in the driveway, I tried to use 1st and got the same results. I also noticed it was difficult at times to find reverse, but I would eventually find it and it would work fine.

Has anyone had similar experiences or have any idea what may be involved??? Complete rebuild of the trans? Or will I be lucky with a clutch related issue?? Any help or advice is greatly appreciated.
yep my t5 did it would go into gear once it got going it would pop out of 1st
had it check out everything was fine but 1st gear was shot
yep my t5 did it would go into gear once it got going it would pop out of 1st
had it check out everything was fine but 1st gear was shot

Did you end up rebuilding it? If so, do you remember what was replaced?
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I am absolutely no expert, but I can tell you this:

Bought and installed a used T-5 to replace my T-4. Installation complete, transmission shifts fine but not great....a few hics here and there.

I get bitten by the "read it on the internet Good Idea Fairy" and decide to try the Penzoil Synchromesh....

Drained the gear oil that was in it (GL-5) and filled it with Synchromesh. Drove it and it was TERRIBLE and getting worse every mile. Ended up almost un-shiftable after about 10 miles.

Immediately drained the Synchromesh and replaced it with GL-4 Gear Lube. Drove it for a bit and the shifting returned to the previous Good-but-not-great condition....

So that is what I think about Synchromesh in a CJ T-5....tested, FAILED.

(End of the story: Clutch linkage was old, worn, shot. Replaced with all new kit - bell crank, etc -- and HD heim joint linkage/pushrods -- shifts so much better that I don't even care about the little "his.")

Just my experience.

Cheers, :chug:
You may have a problem with the 1st gear set, it also does the reverse gear which is located in the rear of the transmission. Now I grenaded my T-5 using my jeep like a tractor (duh!!!). Any way I used to run gear oil guess what thats not good. The factory service manual says to use ATF Dexron II or better. I have been running that since the rebuild 5 years ok and have had no trouble with the gear box. I have about 40 k on it since the rebuild and I do a lot of dual driving with it (trails and street) I'm also not afraid to beat it a bit and it still holds up well with minum amount of wear.
I agree its definitely the 1st gear. I am able toget it into gear and move forward in 2nd, 3rd and 4th...and I can use reverse as well. Looks like I will be pulling the trans soon. Will have to take a look at the clutch while I am in there.

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