5 speed Tran. oil weght

93XJ2drSport · Oct 14, 2012

I was reading about clutches here awhile back and I remember reading some posts about what people were using for gear oil in thier manual trans....I seem to remember some saying they were using 30 weight engine oil, which seems a little thin....I am currently using Mobil 1 75-90 weight in mine and was wondering if something else would be better.....Trans. shifts fine for the most part, although it can be hard to get in reverse sometimes, a little grinding as synchros line up....Thanks

SteveT · Oct 14, 2012

The motor oil cross is 10W30, synthetic, like Mobile 1. Other options are Redline MT90, Pennsoil Synchromesh...Anything that says it's safe for brass, or yellow metals.

#S194 · Oct 14, 2012

I'm not sure if that Mobil 1 you're using is safe for brass synchros. Could be why you are having trouble shifting. I run RedLine 75w90NS in mine...that's what the RedLine website recommends.

Vanimal · Oct 14, 2012

syncromesh has been working great for me. my trans was pretty hard to shift when i got the jeep, it's gotten a lot better since i changed to syncromesh. the old oil was in bad shape though.

SteveT · Oct 14, 2012

A lot of this was just covered here.

Good info there.

Ecomike · Oct 14, 2012

93XJ2drSport said:
I was reading about clutches here awhile back and I remember reading some posts about what people were using for gear oil in thier manual trans....I seem to remember some saying they were using 30 weight engine oil, which seems a little thin....I am currently using Mobil 1 75-90 weight in mine and was wondering if something else would be better.....Trans. shifts fine for the most part, although it can be hard to get in reverse sometimes, a little grinding as synchros line up....Thanks

I read earlier this week that motor oil 10W30 is the same as gear oil 70W90 (or something like that) because they use a different viscosity unit or scale. Not sure if that is right, but it made sense based on what I have read over the years.
:lecture:
A truck driver taught me that the reverse problem is a need to put it in first gear first, then into reverse to get the reverse gear synchronous so it will drop right into gear without grinding!!!!!

2X_01_Jeeps · Oct 14, 2012

There is no synchromesh for reverse. That's why putting it in 1st before going to reverse works- the syncros for 1st stop the input shaft so you can put it in reverse.
Waiting with the clutch pedal depressed for things to spin down when going to reverse also works. (unless you have a draggy clutch)

93XJ2drSport · Oct 14, 2012

Thanks for the info guys, lloks like what I have now is a synthetic Mobil 1 75-90w that is GL-5 and NOT safe for brass, I will change immediately....Glad I checked on here

souske · Oct 14, 2012

Flush it out with some 10-30, then throw some redline mtl in there, should be good for another 60k

Ecomike · Oct 15, 2012

2X_01_Jeeps said:
There is no synchromesh for reverse. That's why putting it in 1st before going to reverse works- the syncros for 1st stop the input shaft so you can put it in reverse.
Waiting with the clutch pedal depressed for things to spin down when going to reverse also works. (unless you have a draggy clutch)

Thanks for the better explanation. I use to always sit and wait for a minute with the clutch pressed in, but sometimes we forget and get in a hurry. The first gear trick seems to be much faster.

5 speed Tran. oil weght

93XJ2drSport

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SteveT

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#S194

FMR SIERRA CHAPTER HMFIC

Vanimal

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SteveT

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Ecomike

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2X_01_Jeeps

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93XJ2drSport

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souske

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Ecomike

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