Hi all,
i run a 85 ex-US army blazer M1009 while turning i get a loud clunking sound at the rear,this doesn't happen all the time.When it does happen the drive seems to stiffen at the rear axle.Anybody got any ideas????????

 

My bet is on a genuine locker in the rearend.

*EDIT* - Here ya go: DetroitLocker.com

 

Hi,
thanks for the answer.Being from the other side of the big pond(England).I take it the diff is up the creek????.If so.is that the complete diff or just a cog or two?

 

From the symptoms you described, it is an exact match to a perfectly working detroit locker. A locker is a solid connection between the two axles. When it gets resistance - ie. during a turn, the cogs release from each other - before the release you will feel it binding, hear an associated clunk when it releases, and a faint clicking while one wheel is turning faster than the other during the turn.

I think that if you were to pull the rear cover, you wouldn't find the typical diff gears found in normal open differentials. If you open it up and find peices of metal... Well, then you may have to look into a replacement diff (and or ring gear etc). But if it only happens when you turn, it mostlikely is a locker in the rear end.

 

Hi,
i take it when u talk about a "locker" u are refering to a "limited slip diff"? The diff has never made any noise until about 2 weeks ago.So i presume it has a bog standard diff...which is now up the creek.

 

Ok. Sorry, I took your post to mean that you just aquired this Blazer and it has this clunk, not that it just started. I miss understood. If it has just started, then I'd say it's time to pull the diff cover off and see what's floatin' around inside there.

Being that it is an ex-US Army Blazer, it probably has a 12-bolt rear end in it. 12-bolt components are pretty cheap and easy to come by so you shouldn't have a problem buying from any of the online retailers (Jegs, Summit Racing, etc).

If you can, take some pics of the inside of your diff. Would be cool to see how one comes apart! Be prepared for a shower of diff lube to come out of it (unless it is bone dry and that is what caused the thing to blow up in the first place).

Good luck!

 

Hi,right i've had the diff cover off.I have a locking diff.If anyone has a copy of the Us army tech manuals it's fig.113 in TM9-2320-289-34P,differential lock assembly component parts (M1009).The part no 12 on the pic has half it's teeth missing.Which is the best way of repairing this? A complete diff or strip the diff and replace parts 12,9,5x2???

[IMG]local://upfiles/513/4074BB7A78884FA898940B4FE75CA53F.jpg[/IMG]

 

Yup, that'll do it. You should be able to replace all of the diff internals without pulling the diff housing out. You will have to pull the axles out part way so that you can get the rest of the components out, then you have to pull the diff pin and the rest should rotate out. You may want to drop off the driveshaft as well to make it easier to rotate the diff.

 

Hi,thanks for the info.Attached is a page from the us army parts book.The items i,ve marked in red,is that all the bits i need to get hold of? or do i need more.Plus have you got any where over there where i can source these parts?

[IMG]local://upfiles/513/89E897B2B38E4D4CBB16CF1A751564E7.jpg[/IMG]

 

Well, here's a handy reference I found while trying to track down some parts for your rear diff:
M1009 - Front & Rear Diff Replacement

I'll keep on looking. I could give a call over to a military auto recycler place I know of and see if they have a full diff. That would probably be the cheapest way to do it, but you would have to setup the diff again (shims & new bearings)...