Extra quart of oil in the Rear HP D44

[much2real]

High Pinion rear?????? Didn't think there was any such animal.

x2

 

[BrettM]

High Pinion rear?????? Didn't think there was any such animal.

there's not stock. it's custom.

 

[explorer]

Use synthetic and add the extra quart. we had the same problem (looseing pinion bearings) in a 9' Ford in the dragster - probably because the acceleration moves the oil to the back of the case, uncovering the pinion bearing. i beleive synthetic is more resistant to foaming - and I know it has better "cling" providing lubricant even when uncovered.

I forgot to mention the link between synthetic and foaming in my other post.

During my tenure with Jeep, they were always updating this or that, one of the things being various RTV formulations. We had 3-4 different types at any given time based on the application. Anyways, at one point, there ws an incompatibility between a certain RTV and the factory fill of 75-140 synthetic that caused excessive foaming. I believe it was with the orange RTV that the original assy. was done with(don't hold me to that though). The factory recommended RTV from that point on and still I believe is a grey RTV. This issue was also believed to be partly to blame for the very common problem of brg. failure.

 

[Kejtar]

I forgot to mention the link between synthetic and foaming in my other post.

During my tenure with Jeep, they were always updating this or that, one of the things being various RTV formulations. We had 3-4 different types at any given time based on the application. Anyways, at one point, there ws an incompatibility between a certain RTV and the factory fill of 75-140 synthetic that caused excessive foaming. I believe it was with the orange RTV that the original assy. was done with(don't hold me to that though). The factory recommended RTV from that point on and still I believe is a grey RTV. This issue was also believed to be partly to blame for the very common problem of brg. failure.

Umm that sounds like BS as I just drained synthetic Valvoline from a diff that was sealed with orange rtv. Unless that reaction was with specific brand of synth oil (plus another question is which vehicle came with synth 75-140 in the axle from factory?)

 

[Capt. Nemo]

I run a HP cover on my standard rear. When I originally filled it up, I filled it until the gear oil ran out of the fill hole. This is a whole lot of oil, especially since the oil also lubes the outter axle bearings. Well, for about a week after I filled it up, it puked oil out of the breather tube every time I drove it. It eventually it stopped, but it was alot of oil. I'm swapping out the axles this weekend, so I'll be re-filling the axle to an acceptable level.

All that to say that I know I overfilled the axle, and I've had no problems other than oil puking everywhere for a few days.

 

[xjspyder]

To answer the question above,some later ZJ's, most WJ'S ,all WK's and most KJ's come factory filled with syn 75-140.I would run a HP cover and just not fill it all the way up,as stated eariler.

 

[BrettM]

I run a HP cover on my standard rear. When I originally filled it up, I filled it until the gear oil ran out of the fill hole. This is a whole lot of oil, especially since the oil also lubes the outter axle bearings. Well, for about a week after I filled it up, it puked oil out of the breather tube every time I drove it. It eventually it stopped, but it was alot of oil. I'm swapping out the axles this weekend, so I'll be re-filling the axle to an acceptable level.

All that to say that I know I overfilled the axle, and I've had no problems other than oil puking everywhere for a few days.

any idea how much it dropped before it stopped puking?

 

[Capt. Nemo]

any idea how much it dropped before it stopped puking?

At least half a quart in the driveway... Who knows how much on the way to and from work :laugh3: It almost had 3 quarts in it initially. When I swap out the axle shafts this weekend, I'll measure out the old oil when I drain it.

 

[jammerjamesharmon]

Ummm neither. Use the HP cover and don't fill till it flows out, but add the right amount and then a little bit more to account for the angle change.

Lots of good info and input. The above makes total sense and that is what I'll do, along with synthetic oil. My added oil fill plug is not a waste; I can use it to put that little extra in. Why risk it, and with out ya'll I never would have thought about this.

Thanks.
james

 

[explorer]

Umm that sounds like BS as I just drained synthetic Valvoline from a diff that was sealed with orange rtv. Unless that reaction was with specific brand of synth oil (plus another question is which vehicle came with synth 75-140 in the axle from factory?)

I'm just passing on info that we were given. And starting around 96 or so, all axles were factory filled with the synthetic. Another thing I forgot to mention, the reaction was with uncured RTV meaning the problem only existed with a fresh service of the diff oil. I'm not just making this stuff up.

 

[Kejtar]

I'm just passing on info that we were given. And starting around 96 or so, all axles were factory filled with the synthetic. Another thing I forgot to mention, the reaction was with uncured RTV meaning the problem only existed with a fresh service of the diff oil. I'm not just making this stuff up.

Hmmm that is interesting though. I wonder if it has to do with different RTV and or Oil used by the dealership. Or maybe I don't see that beacuse I ussually don't drive my jeep right after diff fluid change.

 

[PFunk242]

Ok this pretty much goes along with this thred. I am going to be shimming my Chrysler 8.25 in the next few days. Should i possibly add a new fill hole to my diff cover or will the current level be ok untill i change out the diff fluid again? If i add another fill hole how far up should i place it? I am planning on shimming the rear alxe 6 deg.

Thanks