Rear end flush

[chevy the kid]

Hi,

Does someone know at how many miles it's necessary to flush the diff?

My car have 75000miles and i don't know if it had been flush.

I have a bottle of additive(gm 1052358), i want to run with 80w90 already with additive for lsd.

Does it's good or it's better to go with oil without additive?

THX

[cam98aro]

Re: Rear end flush

do you have a LSD?

if you do then you NEED the additive, if you dont, you are wasting your money

i think they call for either 75k or 100k for diff fluid

i used 75w 90 in mine, an it has been fine

[chevy the kid]

Re: Rear end flush

Yes i have a lsd, rpo G80 with a 3.42 rpo GU6.

If the flush is at 75000 i'm still on the time.

On my french manual it say to flush it every 9000....

What the tool to view my liquid level? 3/8?

[notsonic]

Re: Rear end flush

to open the fill plug, just stick a regular 3/8" drive socket wrench or extension into the hole, works perfectly.

the diff cover bolts are somewhere between 11mm and 15mm. you need to take it off to change the fluid because there is no drain plug.


i just filled mine with 75w90.

if you have a clutch type differential (found on the 93-97. eaton or auburn) you need the lsd additive.

ive read conflicting opinions on wether or not its needed for the gear type zexel differential.


heres a good writeup:
http://www.bfranker.badz28.com/fbody/lubeoil.htm

[Jaymatic]

Re: Rear end flush

I've always thought you were supposed to change the gear oil every 7,500 to 15,000 miles depending on driving conditions. Now I know there's plenty of people who own cars for over 100,000 miles and never do it, but I don't think those people really know that you should, or really care to spend the little time and money for maintaining optimal performance.

As far as a "flush" for the rear end, I don't think it would be necessary unless the oil in there now is in real bad shape. I'm not sure how you would even go about flushing the diff... maybe there's something I don't know about that? Just doing a fluid change should be fine. I don't think my car ever had it done before I owned it and when I changed my gear oil at about 73,000 miles everything looked okay inside the diff. I use a synthetic 75w90 gear oil (Royal Purple) in my open diff.

[HeadyFirebird'00]

Re: Rear end flush

i flush mine every 40-50,000 miles or so. if you have LSD then eat some cuz youll trip your face off

[cam98aro]

Re: Rear end flush

just buy a pump and pump the old fluid out and the new fluid in.. it saves time, and you dont have to replace the gasket, which can give you leaks in the future if you dont put it on the right way

[chevy the kid]

Re: Rear end flush

Ok many thanks, i already have the gasket. I will do it on the month

[landj]

Re: Rear end flush

As far as a "flush" for the rear end, I don't think it would be necessary unless the oil in there now is in real bad shape. I'm not sure how you would even go about flushing ...

ooh.. I know: enima.

[crushedout]

Re: Rear end flush

My haynes manual says to check it every 15k or once a year and change it every 30k or every 2 years.

[chevy the kid]

Re: Rear end flush

Every 30000... So my rear end is near his death, no?

[landj]

Re: Rear end flush

Every 30000... So my rear end is near his death, no?

No... 30,000 is a good guide to keep it in good health, if you don't change it, it doesn't mean you won't get lucky.

[cam98aro]

Re: Rear end flush

Every 30000... So my rear end is near his death, no?

mine went 120k and about 30k with about 1/4 of the fluid it should have

[crushedout]

Re: Rear end flush

I changed mine at 75k or so and never touched it again until I broke the pinion at 150k so I think you'll be ok for quite a while, just change it and do it a little more often than I did.

[chevy the kid]

Re: Rear end flush

Does it's difficult to change the pinion?