I need to pick your collective brains. Last year I blew third gear on my jeep (258 on gas, T5 box). I spoke to the previous owner who expressed surprise that it blew at all- he said he had it rebuilt only the previous year.
He was also surprsed to learn that it had 90 weight gearbox oil in it- he had specifically told his mechanic to use ATF.
Anyhoo, I got new gears and rebuilt the box myself, and used synthetic ATF, as per the current wisdom of the day.
Then it started to make some bearing noises after it warmed up, so I have yanked the gearbox out again to fix it properly. There are some signs of wear around the bearings, not a lot, and some crud at the bottom of the box.
So, my question is: should I
a) replace the bearings, (can I leave that bastard main bearing as it is?)
b) slap it back together with 30 weight oil, or
c) all of the above?
What are your views? (I do like a good repair.)
BTW, I am sticking with the T5, despite its reputation.
I have stuck to the T-5 as well because I love the overdrive...
I use only 10W40 motor oil in it and have great results.
If it were me, I would replace all the bearings/small parts, check for exsessive wear on any gears/parts and or weigh the pros and cons of repair vs replacement with a reman unit or a World Class T5
I was told that ATF was the go for these boxes, and several websites confirm this.
I like the 10W40 motor oil idea, and I think I will replace all of the bearings (except the difficult one glued in the case) and give it a go.
Thanks for your help.
When the original T-5 in my 86 CJ died at 58K, I went to a large Jeep salvage yard where they had sold transmissions with an exchange/core deal for remanufactured units. All work was subbed out. I didn't have 15 hundred at the time for a new one, so at $750 plus core, this seemed like the way to go.......anyway, when I did the exchange, I saw "only 10W40" writen on the unit. I always used 90weight gear oil in the old one. I scratched my head, pointed at it and asked. He said that they would not warrenty it unless I used 10W40 motor oil it it....I said OK and did. I guess, because it is lighter weight, but it shifted so much better than my last one. I change the fluid in it about every 20K miles....so far so good. This reman unit now has more miles than the first and runs great.
One book will say ATF, one will say gear oil, while another will say something else.....oh well, I still use gear oil in the t-case.......hummm, I wonder.
Hmmm, that's interesting. What about the T176? I've got 90w in that jeep too? Any takers on this one (thanks for the reply eddie, I've also read that you were to put ATF in the t5. but couldn't bring myself to do it)
85 CJ7 258, borla header, Team Rush, MC2100 ,optima batt, Warn 8274, agr super box 2 & pump, T5 w/ B&M shifter, centerforce 2, superior 1 piece axles, warn hubs 2.5 in lift, 31" BFG MT
From what I found ATF is used only in the World Class version of the T-5 due to different bearings and synchros. I put 90W in my T-5 as per one of the manuals I had and it blew not too long after, may have been coincidence. I have no idea how the previous owner treated it but it supposedly had been rebuilt two years earlier. When I had it rebuilt the shop put 30W in it and said that they wouldn't warranty it unless 30W was used. With the 30W it has performed great for the last six months and shifts very smooth. This is just my experience and what info I have found so I may be wrong. Good luck.
Okay Just re read three of my manuals here to double check myself. Quote "all manual transmissions except the t4 and t5 which use dexron ii automatic transmission fluid, use 90 weight gear oil". I have been using ATF since day one in my 84 CJ7 T5 and have had no problems as of yet (200,000+ miles). I think i'll be sticking with the red goo.
I drained the T5 on the CJ7 I just bought & it had nasty, stinky gear oil in it. I don't think it had ever been changed. I just put gear oil back in it, but now I'm wondering if I should drain it again & use ATF.
I should also use ATF in the Dana 300, correct?
1983 CJ7 AMC 360, T-5, Dana 300, Dana 30, AMC 20
Warn XD9000i, RE hand throttle, 1" body lift, OBA
Hey folks....I currently run a T-176 in my 84 and am wanting to upgrade to a 5 spd. Having done much research on the T-5, I have decided to go with an AX-15 out of a newer Jeep. The output shaft of the AX-15 is the same as the 176...should bolt to the Dana 300 T-case just fine.
I just had my T5 rebuilt ( destroyed 3rd and its associated part). The Gear Shop in Long Beach did it for me and Gary is very knolegable with jeep parts. He said there has been great debate of which fluid to use but he has not seen ANY HARM done by using the ATF and so that is what I put in it. He said the 90 and 40 weight oils tend to load up the gears and that my contribute to early failure of the already weak 3rd gear.
84 CJ7 Laredo 258/T5 herced tub 86/D44 4.5"RE lift, 33Xterrains and a TWoods CV driveshaft Custom bumpers and tire rack.[COLOR=Blue]Blue Jeep Club #140[/COLOR]