Differential and T-case oil (1 Viewer)

[RedJed78]

Other than synthetic, what is the optimal weight for temperature range of 10*f to 95*f
Is it OK to use gear oil intended for limited slip differential or traction modifiers for a differential that's open or in the transfer case?

 

[Tools R Us]

90w is fine, I use the cheap stuff and change it more often.

 

[ZackR]

I have 75w90 in mine, seems to work just fine. Cheap and change often seems to be the route many folks go with on the T case and differential oil. The limited slip additives won't cause any issues.

If you haven't done this job yet be sure to loosen the fill plug first. Also don't be surprised if the plugs are difficult to remove. I replaced mine with the hex versions so it'll be easier next time.

 

[thetoyotaman]

Don't know about your market but be careful about straight 90 weight that it is not GL-1 rated. Most I see are GL-1. You need a GL-5 80W-90 rated oil for diffs and a GL-4 or 5 75W-90 for the transfer per the manual and the transfer might sound a little whiny without synthetic.

 

[RedJed78]

I have 75w90 in mine, seems to work just fine. Cheap and change often seems to be the route many folks go with on the T case and differential oil. The limited slip additives won't cause any issues.

If you haven't done this job yet be sure to loosen the fill plug first. Also don't be surprised if the plugs are difficult to remove. I replaced mine with the hex versions so it'll be easier next time.

Yes I have done this before. I had to use a breaker bar because a simple, standard length ratchet didn't give me enough leverage and I was starting to round off filler bolt. A breaker bar is a must if it's the first time someone does this on the diffs.

 

[ZackR]

This time through be sure to torque to spec, with a new washer. Save yourself from the breaker bar next time. Mine were also a major pain the first time and I ended up needing an impact wrench after trying everything else. No idea what the previous installer was thinking putting them on that tight.

 

[bicycleagent003]

Bear in mind the TC is aluminum and the plug is steel. Meaning, use a new crush washer each time on the TC for sure and be cautious with torque. Err on the side of less torque, you can always go in and tighten another eighth of a turn later.

 

[inkpot]

There IS a torque spec for those plugs. Low 20s for Aluminum case and low 30s for steel case. It feels light when you set it but it works just fine.

 

[Corbet]

Unlike many I prefer synthetic in both my T-case and diffs. I have enough PM to do on our family fleet so I like longer service longer intervals. All my breathers are extended, chances on contamination is low. The Redline 75-90 I dropped out of my t-case with 125K+ looked brand new last summer.

 

[Rifleman]

There IS a torque spec for those plugs. Low 20s for Aluminum case and low 30s for steel case. It feels light when you set it but it works just fine.

Front/rear diff drain and fill plugs is 36 foot pounds

 

[GeoRoss]

There IS a torque spec for those plugs. Low 20s for Aluminum case and low 30s for steel case. It feels light when you set it but it works just fine.

I put a nice crack in my transfer case over torquing the fill plug.

 

[grizzlygibbs]

I put a nice crack in my transfer case over torquing the fill plug.

Yup, my fill has a crack in it as well. Makes me sad.

 

[Hornd]

Differential is a closed system, so if level is low, find out where it is going before adding more.
These are a nice upgrade:

Add the Allen head (Hex Head) that fits, to your on board tool kit.

 

[GeoRoss]

Yup, my fill has a crack in it as well. Makes me sad.

I used JB weld and sealant for a year. I later had it welded. It's held for 7 years or so.

Watch your torque!

 

[RedJed78]

Unlike many I prefer synthetic in both my T-case and diffs. I have enough PM to do on our family fleet so I like longer service longer intervals. All my breathers are extended, chances on contamination is low. The Redline 75-90 I dropped out of my t-case with 125K+ looked brand new last summer.

PM?

 

[ZackR]

Preventative maintenance.

 

[Corbet]

^ what he said.

 

[Proven]

What size bolt are the drain and fill plugs? I need to drain mine and I am not sure I have the right socket.

 

[LS1FJ40]

I think it is 21 mm. Maybe 24 mm. You should replace it with the Allen head plugs.

 

[LS1FJ40]

Or is it 19mm...?