Power Tour. Rearend help!

[teamplex65]

65 pontiac tempest
200r4 transmission
12 bolt posi out of 66or 67 chevelle

3 years ago we installed the rearend and filled it with fluid. it leaked out of the seal (6 inch puddle if it sat for a month). We used 80/90 weight castrol rear end oil the first time. The puddle was more of a petpeave than harm so I decided to replace the seal before Power tour. Had a shop replace the seal and ever since then a problem has occured.

When turning slowly in forward or reverse the axles are "popping" like they are binding up. If you look at the wheels while doing it they hop a little. They added friction modifier which they think "may" be the cause. Now it has occasionally started doing it more obvious at speed (when it pops it sends the rear end of the car to the left). It seems to do it at speed when on a hill. I have tried to decipher if its only up hill/turning/slow or fast speed but it seems like it may be doing it more and more.

I may not be checking this as much but we are 2 hours from Springfield and are looking for a place possibly to take a look at this or with an idea. I dont claim to know everything about cars so I dont exactly want to tear this apart without someone that knows what there doing.

My brother-in-law may be answering ? as well as he is at a computer more often back in des moines. Brother-in law thinks the pinion may not be set deep enough and it is hoping.

My number is 515.577.3094

Steve

Thank you for any info you can provide

[72Z/28]

Well my had the same problem twice, and he ended up replacing the rear end. The annoying thing is that it is an intermittent popping noise on slow turns. It used to come and go.

[teamplex65]

hmmm, not the answer i was looking for. we are heading back to our home for the night and are going to look more. we thought also it may be a brake shoe that came loose and binds easier at slow speeds. hoping that for an easy fix. we will see.

topeka tomorrow. i guess we may be looking for shops on the way there or in topeka if brakes are not the answer.

[staged67gspwr]

Is this a posi rear?did you use the limited slip additive along with gear oil?my friend had the same issue and it was cause he didnt put in the additive.

Thanks

[4mul8ion]

Here are my 2 cents, priced accordingly.

By what you are describing, I don't think the replacement of the pinion seal is the source of the popping. Typically, problems from pinion seal replacement first show up as a whining noise coasting in a straight line from about 60 mph to about 50 mph then get worse from there.

The thing that I am suspecting is either the spider gears (small gears inside the differential) or the posi clutch pack. Starting with the easiest first, if you forgot to add the posi additive originally and put it later, it sometimes takes awhile for the additive to get in between the posi clutches and the clutch plates, especially if you have a tight posi. Gently driving around in circles will help the gear oil / additive to work its way in there. I would guess that if that were the problem, you should see an improvement in the popping pretty quickly (couple of circles). If not, that isn't it. Too much additive can cause other problems so don't add any more than what is called for.

If the roundy-rounds don't seem to help, consider this. You were saying that sometimes the rear kicks to the left (car pulls towards the right?) when this happens. I'm thinking that something could be wrong with the passenger side spiders or posi clutches causing the car to pull right (rear to kick left). If you can, jack up only the passenger side rear tire and try to turn it by hand using the lug nut wrench through the lugs. If you can't turn it and the car wants to come off the jack,stop, the posi clutches are working and something is wrong with the spiders. It can be as simple as some crap is getting wedged in mesh or as complex as bent or broken teeth. If you can turn it and the tire sticks / slips, something is wrong with the posi clutches. Sometimes the clutch material "unglues" from its ring causing the stick / slip. Either way, the axle housing needs to be opened up to be inspected.

Its probably best to check the driver's side too.

[lt1chevelle]

my bros truck did the same thing you are discribing and he ended up blowing the posi up. when he would drive it the right side wheel would like wabble kinda like you saying.i would stop driving it and look at the gears and posi unit. my bro ended up pulling the truck in the drive way and on his was turning around he blew 2 holes in the diff pan and all the gears were shot in side. just my o2

[chevelle71]

It is a posi trac with 3:73 gears and yes it has the fluid additive in it. And it should have enough miles on it now to have the additive worked in they drove from DesMoines to Little Rock and now to Springfield.

[staged67gspwr]

It is a posi trac with 3:73 gears and yes it has the fluid additive in it. And it should have enough miles on it now to have the additive worked in the drove from DesMoines to Little rocka and now to Springfield.


Hmm so maybe there is something wrong with it then,im really sorry to hear this,i hope you can fix it and all goes well.

Thanks

[chevelle71]

So, if he can make it to Topeka. Does anyone have a shop they know of or a garage with tools that could possibly be used? Thanks for the help guys!!

[4mul8ion]

Just another thought. Maybe its a bent axle shaft. Any recent hard hits with potholes or curbs?

[paul67]

A friend of mine who works in a gearbox axle rebuild shop, only uses the mopar dealer supplied friction fluid, as all others they end up with the axles coming back, it sounds like it's that as my dodge ram diff is doing it at low speed and he's say to put that in, yours would poss need flushing out then re filling.

[chevelle71]

We used a Ford modifier, that I think would be similar to your Dodge stuff.

[TonyHuntimer]

I don't know anything about rebuilding rearends, but if the shop simply removed the yoke from the pinion, installed a new seal and re-installed the yoke...it's possible they got the yoke torqued too tight and now the "crush" sleeve is bound. Was the shop just a general shop, or were they rearend specialists? Aparently it's easy to get the crush wrong and it could be serious if driven too much like it is.

Tony Huntimer
RaceHome.com

[teamplex65]

ill start off by saying thank you everyone.

we have tried the figure 8's with no luck except looking stupid to many people (but i didnt care). it was much cooler today with rain and less hills. it did it way less than the previous days.

we talked to a guy at Currie rearends and when I mentioned to him that we used Ford friction modifier he said that was the problem.

he said we had to use gm or generic friction modifier. seems weird that fluid would make the difference but we are hoping. we drained it and have the seal drying right now in the parking lot. we did find a few metal pieces in the housing but nothing over the size of grape nut cereal (5 pieces). none of the teeth we can see had any missing notches. adding fluid tomorrow and we will see.

stay tuned

[jasonsnova]

ive been there...(and actually mine is getting fixed today as we speak) your problem is that the shop either tightened the yoke to much or not enough, so either it has a loose pinion bearing now or a tight one and a crushed cruch collar, problem is that some people dont realize is that the pinion yoke torque is se in ft lbs of drag.....not torqued, if i had to guess id say it was over torqued, your gonna need to get it to a good rear end shop tear it down install a new crush collar and reset up the gears.......good luck

[teamplex65]

it did it 3 times early yesterday and has not done it since. I find it hard to believe that a little 4 oz bottle of friction modifier can do this but I guess.

thanks everyone for the help. I am planning on finishing the trip and tearing it down since we found a few little pieces of metal in the rearend when draining it.

thanks again everyone.

[teamplex65]

i know this is going to be moved but i will reply with what the problem was found to be and what the metal shavings were.

[TonyHuntimer]

Good luck and have fun!

Tony Huntimer
RaceHome.com

[oestek]

I've had Auburn diffs make terrible noises on synthetic fluid, only to go away after switching to non-synthetic. Turns out the recommendation was in the instructions... go figure.