XC92
Proven Member
- 1,573
- 358
- Jul 22, 2020
-
Queens,
New_York
I need to replace the gear oil in my '92 Talon TSi AWD's rear diff as one of the final steps in a restoration project I've been working on since the summer. The car sat undriven for over 5 years, and before that probably didn't have the oil replaced for at least 5 years.
So I'm wondering if it makes sense to first replace the old oil with "sacrificial" gear oil, drive that for a while, and then put in fresh new oil, to clean things out.
I actually did this already with the trans and t-case when I dropped them a while back, replacing their old oil with Carquest Grease and Lube EP 90 GL-4 Gear Oil, which I intend to flush out and replace with Mitsubishi MTF 75W-85 for the trans and Redline 75W85 GL-4 gear oil for the t-case.
The "permanent" oil I'm going to put in the rear diff is Redline 75w-90 Synthetic Differential Gear Oil, which RTM recommends for my situation, a stock 1G DSM that it's going to be raced or driven too aggressive. I already have it, bought it a few months ago. It's GL-5, per FSM spec.
If using "sacrificial" oil this way is ok, can I also use the same EP 90 oil I put in the trans and t-case, even though it's GL-4 and the rear diff calls for GL-5, since we're only talking a few hundred miles, tops, and probably not even that much?
Or does it have to be GL-5, even for such a small number of miles? Or am I wasting my time doing this and should just put in the Redline GL-5 and be done with it?
Btw, either way, is a pump pretty much necessary to get new oil in the rear diff, or is there enough room to put a small funnel in the fill hole and slowly pour it in--or perhaps use a long flexible tube out the side or rear of the car (which should be fun when it's 35 degrees out)?
So I'm wondering if it makes sense to first replace the old oil with "sacrificial" gear oil, drive that for a while, and then put in fresh new oil, to clean things out.
I actually did this already with the trans and t-case when I dropped them a while back, replacing their old oil with Carquest Grease and Lube EP 90 GL-4 Gear Oil, which I intend to flush out and replace with Mitsubishi MTF 75W-85 for the trans and Redline 75W85 GL-4 gear oil for the t-case.
The "permanent" oil I'm going to put in the rear diff is Redline 75w-90 Synthetic Differential Gear Oil, which RTM recommends for my situation, a stock 1G DSM that it's going to be raced or driven too aggressive. I already have it, bought it a few months ago. It's GL-5, per FSM spec.
If using "sacrificial" oil this way is ok, can I also use the same EP 90 oil I put in the trans and t-case, even though it's GL-4 and the rear diff calls for GL-5, since we're only talking a few hundred miles, tops, and probably not even that much?
Or does it have to be GL-5, even for such a small number of miles? Or am I wasting my time doing this and should just put in the Redline GL-5 and be done with it?
Btw, either way, is a pump pretty much necessary to get new oil in the rear diff, or is there enough room to put a small funnel in the fill hole and slowly pour it in--or perhaps use a long flexible tube out the side or rear of the car (which should be fun when it's 35 degrees out)?
Last edited: