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I know the front axle of a QT2 has a drain plug but why doesn't the rear. Is there different covers that can be purchased with drain plugs? If I could get one so I only remove the cover once it would be nice. The front axle is easy to drain no mess but his does one check that the fluid is 1 inch below the fill port/hole?

Also I know there is a cork gasket you can get, has anyone used it verse the RTV? Any feelings on it?
 

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I thought you had the 5.7 Liter with QD II? If so, there are really no rear differential covers available on the market. If you have QT II, then any Chrysler 8.25 rear differential cover will work (according to GetLost4x4). The rear differential is very easy to do though. Unscrew the 10 bolts (12 if you have QD II), drain the fluid, clean all old gasket of differential cover and axle where the cover bolts on, apply new rtv, screw in 10 bolts and fill differential with new fluid (add friction additive if you have a QD II).
 

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Simple Pan Gaskets are easy to overtorque and develop leaks, or develop leaks later on, thats why so many manufacturers have switch to RTV.

I've tried both pan gaskets and RTV for trans pan (similar type of sealing) and more often had problems with the pan gasket leaking. Install the pan gasket dry, no additional sealant to help them, it acts as lube and lets the gasket get forced out between bolts as you tighten. As well, tighten very little, I've squeezed out pan gaskets using the spec torque with a torque wrench.

Because of that, and how infrequent I've changed axle fluid, I've only used RTV for the axle covers.

Drains in covers often don't extend down all the way to bottom and will leave some fluid trapped when you drain it, as well, its just another thing to spring a leak, especially offroading where the axle can scrape along things, its just another thing to catch and get knocked lose, creating a leak, or so the thinking goes.

The make aftermarket drain plugs that you can add, by drilling a hole and bolting it through the hole with seals and their is a plug in the center. The curved surface of the cover would be likely to leak if you try one of these devices, and I would think it would be even more likely to get knocked loose on the axle then a covered designed with a drain plug.

A small fine wire brush, about the size of a toothbrush, makes fast work of removing the left over RTV, they even make a gasket remover spray, which seems like paint stripper in smell, feel and result, when I have used it, so obviously you have to be careful with it, but it removes left over RTV quickly.
 

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Discussion Starter #5
Thanks for the info.

Correct me if I'm wrong but the front axle has a drain, correct?

I have been debating removing the cover or just pump the rear. Here's my thoughts. If I pump I will not get all contaminants. I really don't want to remove the cover (I'm lazy, possible leaks resealing). But I could pump it out refill it, drive it 20-25 miles getting the fluid moving and hot, pump out the fkuid again then refill it.
Any thoughts on that?
 

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Thanks for the info.

Correct me if I'm wrong but the front axle has a drain, correct?

I have been debating removing the cover or just pump the rear. Here's my thoughts. If I pump I will not get all contaminants. I really don't want to remove the cover (I'm lazy, possible leaks resealing). But I could pump it out refill it, drive it 20-25 miles getting the fluid moving and hot, pump out the fkuid again then refill it.
Any thoughts on that?
Did you look in the Owner's Manual ?
 

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I think this is a good question....the change it twice without cover removal.

I would recommend the first change should have the cover removed.
You will find a fair amount of blackened gook in the bottom of the gearcase.
That is actually the grease used during setup along with the dye used to check the pinion depth and gear contact pattern.
The stuff really doesn't hurt a thing.....just seems like a thorough cleaning makes for a better job.
From then on, you probably are OK, like Sal said, vacuuming it out and refilling for several service cycles.

Rob
 

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Yes, the Front Differential has fill and drain ports, both capped with a NPT threaded plug. The plugs have thread sealant on them, don't remember if the FSM said to apply thread sealant to the plugs when putting them back in, I used Permatex Hi-Temp Thread sealant either way. You need a 14mm hex for the fill plug, I think the drain as well, but I forget if its a different size. You need a stubby hex attachment, there is NOT a lot of room for the fill plug, I had to cut the one I got in half with my dremel to get it to fit.

I drained the front on level ground, even poured a few onces of fresh fluid in to purge. When I filled it, I was short a good 8 ounces of the capacity of the diff case. I suspect the case traps that amount of fluid. Next time I plan on jacking up the front of the vehicle after draining, see if I can get the 8 missing ounces to slosh to the back of the diff case and drain.

My gunk was green and grey at the bottom of the rear diff case. Yes, it does appear to be the left over assembly grease washed out and settled to the bottom. The green may have been the grease color, maybe it was something growing in the oil or some contaminant.

When I removed my axle cover, I used Permatex Ultra Black RTV (which was dark grey/mettalic in color, but thats besides the point). The RTV package recommended tightening the pan nuts finger tight and letting the RTV cure for an hour, then torqueing down the pan nuts. I followed the FSM procedures, 2 big ones NOT to miss.

*Clean both surfaces to be sealed thoroughly, Duh

*Apply the RTV bead and assembly the cover to the axle all within 5 minutes, waiting any longer and the RTV will start to cure and will NOT adhere properly to the other surface. (maybe the figure was 3 min, you need to look it up), NOT so Duh, its a good point, and the only times I had RTV leak on me, I did NOT follow that rule.

I did deviate from the FSM, that says to torque the pan bolts right away, I followed the Permatex recommendation to torque them finger tight and wait an hour to torque them down. I figured that would NOT force all the RTV out and let a thin layer cure before torquing it down completely.

I think either way will work fine, finger tight wait an hour, or torque it down completely right away. I think the pan has some divots in the surface to hold the whole surface off the flange. Thus, the pan will NOT force out all the rtv, there will always be some on the surface, or at least on outer edges, that will seal against leaks.

Been 4k miles, no leaks.
 

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I had my XK front wheels on ramps when I did my front diff an TC. Both took exactly to the ounce what the FSM had stated. I to sealed the threads before installing the plugs back in.
Good to know, it appears the Front Diff does NOT have the drain at the lowest point, that having the front of the vehicle raised will drain it completely, while having the vehicle level while draining, will leave some fluid still in the diff.

It appears my transfer case fully drained while level, but I have the NV140, so can't speak for the NV245 in QT2 and QD2.
 

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The rear diff of my QDII has a magnet built in to the bottom of the housing to catch metal shavings. You can only get to it by taking off the cover. ...Something to consider...


:eek:rangehat:
 

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The rear diff of my QDII has a magnet built in to the bottom of the housing to catch metal shavings. You can only get to it by taking off the cover. ...Something to consider...

:eek:rangehat:
Same for QT1 and assumingly for QT2 as well.

I found the same sort of magnetic goop/sludge you find on the magnet at the bottom of a trans pan. No real shavings or splinters, not even sandy grains of metal, but since its magnetic, its likely a very fine metallic powder mixed with some of the grease and goop at the bottom of the case. Trans and QD2, you can argue its clutch material, but QT1/2 there are no friction surfaces, I "guess" its just the finest metal powder ground off the gear faces and contacts surfaces in the axle.
 
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