Just noticed the front of the rear diff(pinion seal) is leaking on my jeep liberty. I am currently running synthetic 75-140 in the diff as called for in my manual, due to my vehicle having the tow package. I don't tow a big trailer, just a small boat and utility trailer. I was hoping to switch to 80-90 dino oil to possibley stop the leak. Would this help stop the leak, and would using the 80- 90 fluid have any adverse effects on my diff?
switch from syn to dino gear oil?
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Originally Posted By: Highline9
i had a pinion leak rear diff in my jeep commander put in amsoil severe gear 75-140 cured my leak. it leaked with mobil in it.
fix the leak, rear end leak is not something to neglect about, unless u get down and check fluid every month.
i had a pinion leak rear diff in my jeep commander put in amsoil severe gear 75-140 cured my leak. it leaked with mobil in it.
fix the leak, rear end leak is not something to neglect about, unless u get down and check fluid every month.
I put Valvoline synthetic into my '89 Toyota truck's rear diff and it started leaking IMMEDIATELY. It slung a big stripe all out under the bed from the pinion seal.
I drained that and put in about 50/50 synthetic and dino and it totally stopped leaking for 50K more miles. It may be a quirk of the Valvoline synthetic gear oil.
I drained that and put in about 50/50 synthetic and dino and it totally stopped leaking for 50K more miles. It may be a quirk of the Valvoline synthetic gear oil.
Originally Posted By: Highline9
i had a pinion leak rear diff in my jeep commander put in amsoil severe gear 75-140 cured my leak. it leaked with mobil in it.
I'm actually running amsoil 75-140 so that option is out.
i had a pinion leak rear diff in my jeep commander put in amsoil severe gear 75-140 cured my leak. it leaked with mobil in it.
I'm actually running amsoil 75-140 so that option is out.
Fixing a diff leak is not that expensive, unless something else is wrong.
Going to a thinner dino will probably make the leak worse.
Mostly, because it is thinner.
If you replace the seal yourself, MARK THE NUT AND THREADS. A punch or chisel mark is permanent, unlike a pen or marker.
Now you can tighten it back without changing the crush washer preload.
It's not a hard job - use care and don't rush.
Mostly, because it is thinner.
If you replace the seal yourself, MARK THE NUT AND THREADS. A punch or chisel mark is permanent, unlike a pen or marker.
Now you can tighten it back without changing the crush washer preload.
It's not a hard job - use care and don't rush.
Last edited:
Originally Posted By: mechtech2
Going to a thinner dino will probably make the leak worse.
Mostly, because it is thinner.
If you replace the seal yourself, MARK THE NUT AND THREADS. A punch or chisel mark is permanent, unlike a pen or marker.
Now you can tighten it back without changing the crush washer preload.
It's not a hard job - use care and don't rush.
I was under the assumption that dino oil, even a lighter weight, would still be thicker than synthetic and might stop the leak. If this is incorrect then I will stay with synthetic fluid. In any event I will probably end up fixing the leak eventually, anyway.
Going to a thinner dino will probably make the leak worse.
Mostly, because it is thinner.
If you replace the seal yourself, MARK THE NUT AND THREADS. A punch or chisel mark is permanent, unlike a pen or marker.
Now you can tighten it back without changing the crush washer preload.
It's not a hard job - use care and don't rush.
I was under the assumption that dino oil, even a lighter weight, would still be thicker than synthetic and might stop the leak. If this is incorrect then I will stay with synthetic fluid. In any event I will probably end up fixing the leak eventually, anyway.
Oh, no that is not how it works.
Anything in the 90 grade range is going to be pretty close to the same viscosity. Same with 140 range.
Anything in the 90 grade range is going to be pretty close to the same viscosity. Same with 140 range.
If you replace the seal yourself, MARK THE NUT AND THREADS. A punch or chisel mark is permanent, unlike a pen or marker.
Now you can tighten it back without changing the crush washer preload.
It's not a hard job - use care and don't rush.[/quote]
what he said.
Now you can tighten it back without changing the crush washer preload.
It's not a hard job - use care and don't rush.[/quote]
what he said.
Originally Posted By: Highline9
If you replace the seal yourself, MARK THE NUT AND THREADS. A punch or chisel mark is permanent, unlike a pen or marker.
Now you can tighten it back without changing the crush washer preload.
It's not a hard job - use care and don't rush.
what he said.[/quote]
and use torque wrench to torque it down correctly, dont do like every other mechanic use impact wrench -_-
If you replace the seal yourself, MARK THE NUT AND THREADS. A punch or chisel mark is permanent, unlike a pen or marker.
Now you can tighten it back without changing the crush washer preload.
It's not a hard job - use care and don't rush.
what he said.[/quote]
and use torque wrench to torque it down correctly, dont do like every other mechanic use impact wrench -_-
Actually, do NOT use a torque wrench on the pinion nut!
That defeats the marks and will mess with the preload!
The punch marks/chisel marks method is not perfect, but is 95% safe. [Use the same nut and washer] I use it with confidence.
So many have use an impact to tighten the nut, crushed the collapsible washer, and now need a complete tear down and set up of the rear end.
That defeats the marks and will mess with the preload!
The punch marks/chisel marks method is not perfect, but is 95% safe. [Use the same nut and washer] I use it with confidence.
So many have use an impact to tighten the nut, crushed the collapsible washer, and now need a complete tear down and set up of the rear end.
getting the leak fixed and found some amsoil 75-90 at napa, I'll change the fluid while I am at it.
Originally Posted By: mechtech2
Actually, do NOT use a torque wrench on the pinion nut!
That defeats the marks and will mess with the preload!
The punch marks/chisel marks method is not perfect, but is 95% safe. [Use the same nut and washer] I use it with confidence.
he is right. to much preload smoke the bearings to little it will howl at the moon.
Actually, do NOT use a torque wrench on the pinion nut!
That defeats the marks and will mess with the preload!
The punch marks/chisel marks method is not perfect, but is 95% safe. [Use the same nut and washer] I use it with confidence.
he is right. to much preload smoke the bearings to little it will howl at the moon.
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