1990 - Rear Differential Oil help!
#1
1990 - Rear Differential Oil help!
I'm getting ready to change my rear diff oil. I don't have the original manual for the truck. This is the first time I've done this task, and am trying to see if I'm on the right track.
The axle sticker code is 19 and tag number is S808D which the specs are:
Axle: Ford 8.8 Capacity: 3800 Gear Ratio: 3.55 - Non-limited slip
Regarding the gear oil weight, all I've been able to find in my Haynes manual is:
"Differential lubricant*
Ford rear axles (conventional and limited slip) Hypoid gear lubricant"
From the research I've done, it seems Redline 100% Synthetic 75W90 is a suitable choice.
Can ya'll let me know if this is a good choice, or point me elsewhere.
Thanks
The axle sticker code is 19 and tag number is S808D which the specs are:
Axle: Ford 8.8 Capacity: 3800 Gear Ratio: 3.55 - Non-limited slip
Regarding the gear oil weight, all I've been able to find in my Haynes manual is:
"Differential lubricant*
Ford rear axles (conventional and limited slip) Hypoid gear lubricant"
From the research I've done, it seems Redline 100% Synthetic 75W90 is a suitable choice.
Can ya'll let me know if this is a good choice, or point me elsewhere.
Thanks
Last edited by SJMAK; 04-14-2017 at 04:13 AM.
#2
It is a fine choice...on a 1990 truck, I would probably save a few bucks and buy the cheapest 75w-90 on the shelf and call it a day.
#3
Senior Member
Manual for my 94 says 80W90 in the rear, which will be even cheaper.
Front calls for 75W90.
Your choice should be fine for both.
Front calls for 75W90.
Your choice should be fine for both.
#4
the way I look at it, I don't change gear lube as frequently as I do engine oil, so I want the best I can afford in there since it has to do it's job for a long time. If you're going to spend $7 or $8 for a quart of regular gear lube, why not spend $10 - $15 for synthetic that (theoretically) you'll get more mileage and protection from. I paid $15 per quart for Amsoil Severe Gear 75w90, which according the the following test chart, was one of the best gear lubes tested. http://www.syntheticoilhq.com/images...comparison.gif
#5
Senior Member
My suggestion is if you don't know the history of your differential, run some el cheapo differential gear oil in it for 10,000 miles or less to clean it out then switch over to Amsoil Severe Gear 75w-90.
As for what gear oil to run in your differential to clean it out, whatever floats your boat. It doesn't really matter in the open differential.
As for what gear oil to run in your differential to clean it out, whatever floats your boat. It doesn't really matter in the open differential.
#6
My suggestion is if you don't know the history of your differential, run some el cheapo differential gear oil in it for 10,000 miles or less to clean it out then switch over to Amsoil Severe Gear 75w-90.
As for what gear oil to run in your differential to clean it out, whatever floats your boat. It doesn't really matter in the open differential.
As for what gear oil to run in your differential to clean it out, whatever floats your boat. It doesn't really matter in the open differential.
I have had customers use the bottle pump to pump out the old lube so they dont have to remove the cover.
If you are going to run "el cheapo" lube short term just to clean it out. That might save a little time.
#7
My 1977 has a Ford 9". It has neither a cover nor a drain plug. I pumped the old oil out of the fill hole with a boat lower unit hand pump, then filled back up. That was 2 years ago. It was the first time the oil had been changed.
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#8
Senior Member
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