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What kind of tranny fluid for a t-5

1300 Views 8 Replies 1 Participant Last post by  **DONOTDELETE**
G
I just have to say that this list is the greatest and has increased my jeep knowledge ten fold. I have a question about what kind of fluid to use in my T-5. I have been using the mopar fluid that the haynes book recommends but I seem to be getting notchy shifting, especially from second to third and it didn't start until I put the mopar stuff in. I have heard that newer T-5's have to use this stuff. Can this be true? I know something is going on because my tranny is getting louder even in neutral as I am coming to a stop, but hey what do I know, I'm just a teacher :) Thanks again for all your help
guys.

Tim 85 CJ-7 2.5 skyjacker, 2 inch body, 32 dunlop muds, herculiner, holley carb and a HEI soooooooooooooooon.

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Hello CJBUDDHA!! I use Dextron III with good results. Even after
a rebuild My T-5 sometimes has a rough 2-3 shift, the guys at the trans
shop said to try Mobil 1 synthetic 10w30 It's all they use I'm going to
try It Hopefully it works!!!
83 CJ7 258/t5


G
I used to use ATF in my old T4. I also added Slick 50 Trans additive and it shifted 10 x better. I also use it in my transfer case. Several of my buds use 90 wt in their case but ATF was what was in mine . The syncro between 2 & 3 goes out in the T 4 & 5.

G
I have been running up and down the same roads as you have as to which oil to
run in the T-5. The best I could come up with is ATF.
I went to the mobil ATF synthetic . About $5.00 a Qt. I been told that
the T-5 does not oil well in cold weather??? and ATF is best??
If ATF is the best I wanted to give it the synthetic to give it the
best chance to live a long life. I will also be changeing this oil
twice a year atleast. My T-5 shifts better than it ever has
Respectfuly I would not use the Mobil 10-30 synthetic . From my motorcycle
days I learned that motor oil does not do the best with gear boxes. The
gear shear of the gear faces on each other will break an oil down fast.
I do run Mobil 10-30 synthetic in my motorcycle with a gear box sharing
the motor oil. Because of the gear shear I change it often.
All of the above is the truth to the best of my knowage/wwwthreads_images/icons/smile.gif
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G
ATF in a T5, use synthetic if you can afford it. Most of your modern aluminum case manual trannies use ATF, nothing much
uses gear oil anymore. One other place that is prone to failure is the input shaft bearing. I had mine go out a couple years ago,
it got into 4th gear which is unfortunately part of the shaft, had to replace the shaft. The T5 is much maligned, but it is in fact a
decent trans if NOT ABUSED. The low 1st gear and OD make it nice. BTW, I got 124,000 out of mine before the bearing went,
always used ATF, and it is not exactly babied.

Brad (from the 4 Wheeling center of the universe, 4 corners USA)
G
Here is what I found out about T5 oil. AMC Manual recommeneds AMC part # 8983-000-000. This is a yellow brown very stinky fluid. This part # became Mopar4549636. This fluid is identical to the old AMC stuff. However, Mopar switched to a third part #, 4874464. This is not the original fluid and looks/smells like gear oil.

Others who know more than I do have pointed out a TSB that was issued back in the mid 80's, I think it stated to switch to ATFespecially for cold weather. Since I have some of the 4549636 stuff on hand I'll be using it till it runs out.

I just bought Mobil 1's 75w-90 gear oil.......I'm doing the entire drive train change over (I hope a case of the stuff is enough @ $62.50 /12qts). ......I'll change over the t/c to mobil 1's ATF. In 1978 my Peugeot (78 504 diesel wagon 4 speed) called for motor oil in the trans....I talked to the dealer and he said that he didn't know why they specified it. He offered that gear oil my be hard to come by (read-expensive) in Europe. He said that they just used 90 weight (which happens to have the same viscosity as straight 40 weight motor oil) hypoid.....BUT YOU COULD use motor oil. The only problem with this is that you cannot mix hypoid and motor oil together.....they foam on contact (try it ....it's very strange to watch)...so a complete change over was required. I'd be leary of using ATF in a helical application (JMHO) and not pumped under pressure (as in an automatic) with an active cooling circuit.......but maybe I'm just "chicken little".
I'm trying to cure that "notchy" second gear shift that seems to plague the 5-speed (I'm not sure of the actual trans....99 TJ 4.0....anyone?). It's really reluctant to shift into second when cold and downshifting is "stiffer" than the other gears at all temps......nothing that a little more time taken to put it in gear or double clutching can't solve. I'm also "sweeping out all the corners" as CJDave would say........trying to squeeze out every drop of potential economy that the beast has to offer since it is a daily driver...17.5 mpg is the current of 60 - 70 mph highway commuting 70 miles round trip a day..(a man must have his dreams /wwwthreads_images/icons/laugh.gif). Others have done this change over for the trans and have reported significant improvements in shifting ease.

My experience is somewhat dated since I haven't been in the trade (left wrenching in 77 for greener pastures) for over 20 years......so some of the lubrication "truths" (like many social truths) may have changed in that time.....so
this has to be put in the opinion slot.....
GeeAea

Figures don't lie ....... but liars sure do figure.
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I hear you GeeAea. I had [have] a hard time feeling good about ATF in my gear
box.
I remember when the Big three where going to ATF in gear boxs for better gas
mileage. Some of them said to go back to 90 wt if you towed anything.
Don't remeber what just remember reading it in the old PV 4 magazines.
G
The ZF 5-speed in my 97 F250 calls for synthetic ATF. The reasoning as I understand it for ATF is because of very tight clearances between rotating parts. Regular gear oil is too thick to get between these parts and does not provide adequate lubrication. The original fluid in my tranny allowed a little too much grinding between second and third gears when it was cold out and the tranny was still cold. I switched to Redline's D4 ATF and am very happy with the results. No more grinding as D4 is formulated for lower temperatures. The local shops which carry Redline wanted around $12/quart but I found it at http://www.redlineoilracing.com for $7/quart.
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