How much power will a stock 8.8" differential take?

[IZwack]

Rotationally, a linear 1/2" from one end to the other end is actually on the small end of things. I remember when I still had an 8.8, it had a lot more backlash than that.

 

[colindo94]

Is it like a ding noise when you put it in gear. Mine does this when I put my trans in reverse. I get a clunk and a ding all at one. I figured it was my dieing A4LD that caused the clunk. But now you all really got me thinking. My tranny also shifts pretty hard. I also seem to have about of a 1/2 of turn in my driveshaft. And I had a shop set up mu whole rear end about two months ago.

 

[Turdle]

Yes, it is a ding type of sound I guess.
I'm going to get a video so everyone can hear it.

there are 4 old guys who go hang out in front of the convenience store to gossip every day-As I pulled out, I heard one of them say "yeah, but his u joints are going"

that kind of noise-

 

[colindo94]

It sounds mostly like a u joint problem, but the thing is I just gor new u- joints when I was doing the SAS and thats when the problem started for me.

 

[Turdle]

dangit-
I just filled it with Amsoil stuff not too long ago-less than 10k
I hate to throw it away-

 

[CDW6212R]

Get the tires in the air and take a closer look. If you think that the rear has too much play, drop the cover and save the fluid. If something is amiss you should be able to find it.

 

[410Fortune]

sure its not the slip yoke in the d shaft making the clunk noise?

 

[CDW6212R]

With the new mixture of parts you do need to keep a close eye out for new issues.

 

[jah81592]

ummm, it seems that's how much I have--

Jon,
I have set up several of these rear ends (around 70) and they are very strong. One thing to note is the gen 2 Explorers have bigger axle shafts and bearings than thier Mustang cousins plus they are 31 spline to boot. Roughly around a 1/4 diameter larger! I alway do several things on a gear change/rear rebuild. Upon initial evaluation I always check the pinion rotation with the rear up in the air. The backlash will be minimal (laymans term-any more than the 1/4" rotation would be too much) I alway set mine initially on the tighter side of things because as they(bearings and gear) breakin they tend to aquire a little backlash usually setting them perfect after the breakin. As stated previously the pinion bearing will mainly generate a vibration at highway speeds and not the clunk which you are describing but if you have a harsh "garage shift" n-1 or n-r then it is definately possible.

Secondly, I never set up a set of gears without rebuilding the Trak Loc. The parts (Trak Loc clutches M-4700b around $42-standard, M-4700c around $140-carbon upgrade) are cheap and I just cant see why you wouldn't do it once you are that far into the rear. Depending on what your application is I would recommend different clutches for an individual basis. This is primarily preventive as if they get too worn I have seen the spiders eat into the carrier. Although the previous statement is the excess, the auto car didn't clunk while engaging a garage shift. So in theory still the only way to get a clunk would be in the backlash. Worn Trak-Loc's will raise hell while turning (grinding and popping if excessively worn) due to binding between the spider and side gears. A normally worn Trac-Lok will just "dog leg" like crazy, just reinstall clutches and roll on.

Last but not least I would at the minimal remove the cover and check to see it the main caps are tightened and there aren't any cracks in the differential or housing,or any side to side movement in the carrier. Recheck torque with a torque wrench to ensure correct specs.

Finally if all looks well then you just verified that your rear is ok. You can clean your carrier and cover very good and catch your good fluid first then you can reuse if you need to. Don't forget the friction modifier even if you use synthetic. This is the way Ford does it and for very good reason. I have only touched the surface and this is not a detailed description on shimming the Trac-Lok clutches or even setting the backlash. This is only to help troubleshoot/eliminate your suspicions with the rear. Oh and to finally answer your question I don't believe you will have a problem at this moment with yours!

 

[rookieshooter]

I really don't think you have much of a problem at all. Go wheel it.

 

[rizzjc]

So what would be the problem if I have rotational "slop" in the driveshaft--

meaning, the driveshaft and yoke turn a bit before the diffy does--

It seems there is slop between either the pinion and ring, or the ring (carrier) is loose.

(cousin Eddie voice) I dunno

Interesting. I think this is EXACTLY what I've got going on .... and now the seal is leaking again too. Could have been from the sledgehammer I used to remove the flange (and replace) the last time I replaced the seal. Oops! I'm subscribing ....

 

[Turdle]

Well today I moved it into the driveway to looky-and no noise at all, whatsoever--

So, I attacked an ac problem. I'm going for a drive a bit later to verify this though--

I ONLY get the cling if actuall rolling in reverse, then shift to drive and go, or actually roll in drive then shift to reverse-
If I just do the shifting and hold it-no thunk
It must move in one direction first to do it--
Does this narrow it down?

 

[IZwack]

I think the problem is user error :

But seriously tho, remove the differential cover, the driveshaft and have some one else rotate the pinion flange while you listen for the "clang" on the other side.

 

[Xan]

Well today I moved it into the driveway to looky-and no noise at all, whatsoever--

So, I attacked an ac problem. I'm going for a drive a bit later to verify this though--

I ONLY get the cling if actuall rolling in reverse, then shift to drive and go, or actually roll in drive then shift to reverse-
If I just do the shifting and hold it-no thunk
It must move in one direction first to do it--
Does this narrow it down?

Dude are you saying you're still rolling back slowly when you drop it into drive or the other way around?

 

[rizzjc]

dangit-
I just filled it with Amsoil stuff not too long ago-less than 10k
I hate to throw it away-

Yeah, that's painful. I've been there a couple times. A lot of money down the drain when you have to toss that stuff out.

 

[Turdle]

Dude are you saying you're still rolling back slowly when you drop it into drive or the other way around?

No-silly-I've been around the block a few times.

I said-the truck actually has to move in one direction, when the direction is changed is when the thunk happens. But ONLY if the truck is moved.
If I hold it, and shift from R to N to D to N to R to N to D = no thunk
If I roll in drive-stop, shift to N then R=clank
If I roll in reverse, stop shift to N then D =clank

It is definitely from the diffy--

 

[Xan]

No-silly-I've been around the block a few times.

I said-the truck actually has to move in one direction, when the direction is changed is when the thunk happens. But ONLY if the truck is moved.
If I hold it, and shift from R to N to D to N to R to N to D = no thunk
If I roll in drive-stop, shift to N then R=clank
If I roll in reverse, stop shift to N then D =clank

It is definitely from the diffy--

Just making sure haha i know some people that drive that way. in my oppion if you're having this problem now before adding more people and you did the U joints i'd deffently open it up and check the tolarences and check for damage or metal shavings. traction lock system have been known to make that noise.
My Z-28 was making noise in the rear and i din't think much of it one hard launch later... i have a ring with a shiny flat part on it where there should be teeth :thumbdwn:

 

[CDW6212R]

That's why 8.8 of a Ford is better than 10 of a Chevy.

 

[Xan]

That's why 8.8 of a Ford is better than 10 of a Chevy.

Haha not really it was a 7.625 and when you upgrade an engine to 400+HP and prep your trans for it but don't think to do any thing to the rear end you're asking for trouble no matter what you got. a ford 9 inch is only good for racing when you build it for it

 

[rocket 5979]

when you upgrade an engine to 400+HP and prep your trans for it but don't think to do any thing to the rear end you're asking for trouble no matter what you got. a ford 9 inch is only good for racing when you build it for it

Where is the BS smiley at again? That stocker 8.8" of Jon's will easily last through the power he is putting down now. The problem he is having is VERY unlikely to be caused by the additional power he is running.





I have seen the 28 spline 8.8" rears live past 600 hp and have seen 31 spline 8.8" rears last past 700 in stock form through an auto.

With a diff brace and upgraded halfshafts I have seen people push past 1,000 hp with the 8.8" no problem.