Just finished my 8.8 swap ran it for 25 miles half of which was at 80, When I stopped, it was so hot I could hold my hand on it for about 3 seconds....Is that normal?!

 

what was this "swap"? the whole axle from 97 4x4? did you check the fluid levels?

 

Well, yes....I had to take the 5.71s that were in in out and put some 3.73s back in it........A guy that races with gfs stepdad did it. Yeah, fluid is good, put 2 whole bottles of lucas in it and its jjjuuuusssstt below the fill hole.....

 

Might want to pull the cover back off and check the clearences on the gears. The rearend shouldn't get that hot.

 

no way should it be that hot.....you may also need to check the fluid level......

and this is why i am adding a rear diff temp gauge....

 

hmmmmmm....How exactly do I check clearance? Im not a rear end person.

There is no roaring or whing or anything back there. quiet as stock one was.

 

that dont mean anything......something isn't lining up correctly.....

 

"Too hot to touch" covers a wide temperature range, probably anything from about 130F and up. 130F is not necessarily too hot for a diff after a long high speed run. I have seen a differential temp exceed 300F during trailer towing. This is DEFINITELY too hot to touch and DEFINITELY too hot for long diff life.

Before you get too exited, measure the actual temperature. One way to do that is with a non-contact infrared thermometer. Harbor Freight Tools has the handheld Cen-Tech IR thermometer on sale for $9.99 (1/2 price). I'm sure that this is not the finest measuring instrument ever made but it should be capable of telling you if your diff is closer to 130F or 300F.

 

I'm betting closer to 130 if he could hold his hand on it for three seconds, lol. 300 -- no way he'd be touching it that long.

Also, you did not do any kind of "break in" on that. I know it's probably the original gearset, but they probably aren't meshing just like they did and so you have to break in the gear faces again. NO WAY you should be doing 80 in them in the first 25 miles. You should be going easy on them for a few hundred miles. Any excessive heat is probably a self-inflicted injury and you should read a bit more about differential rebuilding so you'll understand these things in the future.

 

Definitely. The 300F temperature was given to show a possible range rather than to suggest that it is actually getting that hot.

 

Well, drove to ATL and it was still hot hot. stopped by auto parts store and got another bottle of fluid and EMPTIED it! DANG! how much do these things take!? My 7.5 only took 1.5 bottles! Made it here to West Virginia with no problems....Didnt have time to break it in! My Grandpa died friday night and the funeral is tommarow so I had to get here. It is not the original gearset, came out of a mustang(factory set). my dad drove up in his mountie with me and his was just as hot as mine was after the third bottle was put in when we stopped in Spartanburg SC. So I think itll be ok.

My Uncle was a mechanic for AEP for 20+ years, working on anything from rangers to tractor trailers, he said i would kno in the first 75-100 miles if somthing was messed up!

thanks guys for all the input!

 

I wondered why you said it was almost up to the fill hole with only 2 quarts. 7.5's and 8.8's take about 2 1/2 ~ 3 quarts. Maybe the diff was at an angle when you filled it the first time?

 

looks like you figured it out, for the most part, but i know mine used to get really hot with 4.10s and 35s...

 

Again -- if you don't know what you're doing, you should avoid doing it! Your relatives not withstanding, you didn't seem to even know the fill capacity of the diff!!! How can you expect to know whether it's right when you didn't even take the time to know how much oil it requires.

There is no substitute for researching what you're doing. Period.

 

Excuse me...........As i knew it and as i have done with all other rear ends, you fill it up till it runs out of the hole. I put 2 bottles in and it was about a CM below the hole. figured a CM wouldnt hurt it. Guess I was wrong. Sorry I was wrong with my axle oh great one. Its not like I did the gears myself or anything, thats why I let sumone else do them, Becuse I DIDNT KNOW WHAT I WAS DOING! My 7.5 took 1 1/2 bottles figured the 8.8 wouldnt hold MUCH more.






Bob: It was in the truck whe I filled it, and I guess When I drove it for a lil bit it got into everything properly.




Does the rear end fluid go out the tubes to the outer seals or are there seals on each side of the pumpkin?

 

The lube goes out to the ends of the axle for the wheel bearings. The seals are outboard of the bearings.

 

Ok, well that makes sense now, guess i prolly need to double check it before I leave town!

Thanks Bob!

 

According to the 95 Ranger Owner's Manual, 7.5 and 8.8 axles have the same 5 pint (2 1/2 quart) capacity.

 

hmmmm.... I put 3 in it...wonder where the rest went?

 

In my 8.8 it held 3.5 quarts when it was all the way up to the hole.

 

1) You have lift shackles and other mods that may influence the angle of the differential. The spec is written for a stock Ranger.

2) The fill procedure (in your owner's manual) says that the spec was written for an axle filled to a level between 1/4" ~ 9/16" below the fill hole.

 

Too bad if you don't like it. I'm doing you a favor: if you don't know how much goes in, you don't know if you really filled it. Using the hole only shows the diff is full -- what if something was blocking the axle tube?

You can get as pissed off as you like: but the fact remains you did the job without the proper information. You can complain all you want but that's the facts.

If you're not going to do your homework, young man, you can scarcely complain when you flunk the exam!

Make me the bad guy all you want: but if you don't learn from this, you're even more of a fool than you seem to be acting in this thread.

 

To me....this ^ is the fool......not everybody is a genius such as yourself..........

 

No, those words may be a little strong but they are true. It does not take a genius to fill a differential but it is a good idea to take a little time to find out how much and what type of lube to put in it before doing it.

I put that in the category of wisdom not intelligence. I know a genius that most likely could not change oil in a car.