rear axle overheat

[jammer131]

So we own a 1997 ford Explorer XLT with a 5.0L V8 engine and its AWD. We have been having issues with the rear axle temp hitting around 380 degrees. We first thought it was parking brakes so removed all the parts to it, did not fix it. Next we replaced the calipers, hoses, pads and reran the brake lines from the abs all the way to the back plus the crossover, still not it. What else could be the problem? abs light it on but codes are C1214, C1198, and C1194.

 

[RangerX]

Check the fluid level?

 

[jammer131]

brand new brake fluids and rebuilt the diff but still getting that hot, diff has new fluids and resealed

 

[C420sailor]

Are you sure that temperature is accurate?

That is obscenely hot for a rear—especially if you aren’t towing something heavy as ****. I would expect slightly elevated temps during break-in, but that is nearly double what I would expect. I’d suspect the rebuild…

 

[Mbrooks420]

If your rear is almost 400 degrees you didn’t rebuild it correctly, and it’s going to need torn down again.

Where are you measuring this temperature?

 

[jammer131]

hm ok so may have to rebuild it again but i dont think that will fix it since this problem is happened before the rebuild too. we cant figure out whats wrong. we r guessing atm that the abs sensor for the rear is not letting the brakes release properly. we have an been checking it on the axle itself right between the tires and the diff

 

[C420sailor]

How does the truck roll in neutral? Does it require extra power to get and stay moving?

An IR temp gun should allow you to easily determine if it’s the brakes or the diff

 

[jammer131]

thats how we have been getting the temps. We use our IR therm to the axle and its hitting 380. in neutral the truck rolls fine surprisingly we use to have issues with it not moving and needed help. the ABS light is on but i already mentioned the codes that came up for it mainly at the front or the modules themselves. and again this problem has been happening before we rebuilt the diff and rear brakes

 

[Mbrooks420]

It’s not the ABS not letting the brakes release. This type of truck doesn’t do that.

Check the brakes themselves with the IR. Then check the actual differential. If it’s just the tube between them is shot it’s likely the wheel bearings, although I’d expect this to be noisy.

Also would mean the differential rebuild was a total waste. Stop throwing money at it, and do some logical troubleshooting. Or, take it to a qualified shop.

 

[C420sailor]

Not only that, but for the brakes to heat the tubes to nearly 400°…they’d be insanely hot, and you’d smell them.

 

[donalds]

Just to add
after I rebuilt my 8.8 out of pure curiosity I checked the rear with a IR gun
on the cast iron case it was around 200°f wow
But after a few checks I realized the temp was settling down
Last I checked it was 125°f after a two hour drive seems good to me
Its about as hot as your hand can take but not burn you

May just be breaking in
Gear patterns may be off
Pinion bearing preload way to tight

380° is way to hot

 

[jammer131]

with what u guys r saying i guess we will be taking the entire axle apart including the diff again and replace the bearings, seals and make sure no major damage to the dif itself then reseal everything up and hope that fixes our issue

may have to wait on redoing all of that after i fix the heater core in our 2010 F 150 XLT since that decided to pee all over the floor.... we know its the heater core cause it stinks like hell in the cab from the coolant

ill let you know what happens when we rebuild the explorer again which might be in a week or two

 

[donalds]

I think your pinion preload is way to tight
I'd check there first
Here is a great video

 

[410Fortune]

are you checking the temp on both tubes not just the pass side under the exhaust

Is the housing bent?
Is the vent line clear?
did you replace the wheel bearings?
Have you checked your IR gun for accuracy?

just spit balling here

 

[jammer131]

we been checking it on the driver side since exhaust heat could alter the results. as for the housing its fine, the vent is clear and we plan on replacing the wheel bearing this weekend. the accuracy of the IR gun is as good as it will get since its .1 or .2 off when we were calibrating it using our own body temp compaired to the normal therm used to check for fevers

 

[KeenKilo]

What are break temps/actual diff.

It’s just the tubes that’s are hot?

Driveshaft temp/wheel temp?

Idk isolate moving part temps before replacing things. The parts cannon adds up quick!

 

[jammer131]

we have already replaced all the brakes and on the rear only thing left is the diff and the wheel bearings

when we rebuilt the diff all we did was open it up to do the normal maint on it by replacing the seal and grease it didnt really replace any of the gears

 

[donalds]

Replace pinion seal and tighten the bolt to much and the diff will get hot
I'd check the pinion bearing preload

 

[Mbrooks420]

we have already replaced all the brakes and on the rear only thing left is the diff and the wheel bearings

when we rebuilt the diff all we did was open it up to do the normal maint on it by replacing the seal and grease it didnt really replace any of the gears

You didn’t rebuild the differential at all. Do you consider it an engine rebuild when you change the oil?

You’ve probably have had a differential problem the entire time.

 

[jammer131]

considering i was still in highschool at the time we did that no we didnt think about it so it might b a possibility the diff is bad which might explain y we get some stuttering when turning and it stuttering at times too.