Drive Line Slack?
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Joined: Apr 2009
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From: Northern Idaho
Drive Line Slack?
I am curious about some slack I have between the tranfer case and the rear differential.
When I am driving I can let off the fuel and then give it some fuel and you can hear the clunk of the drive train.
When I got home I set the e-brake and put it in nuetral (6 speed manual) and checked the U joints and all but the rear seemed nice and tight with no slack to be seen. The rear needed 2 8mm bolts tightened a little bit but other then that all U joints are tight with no play.
How ever when I turn the drive shaft I get about half an inch of play in the rear diff and the transfer case before you hear the drive train get stopped by the gears. Both the diff and the transfer case make the clank noise of metal hitting metal.
I have recently changed the fluids on both of these and the fluids looked great and without chunks of metal. No leaks can be seen anywhere and the fluids on both are just above the bottom portion of the drain hole.
I used Mercon 5 in the transfer case (Recommended as the fluid to use) and Valvoline 85/95 gear oil in the rear diff.
Is this normal?
When I am driving I can let off the fuel and then give it some fuel and you can hear the clunk of the drive train.
When I got home I set the e-brake and put it in nuetral (6 speed manual) and checked the U joints and all but the rear seemed nice and tight with no slack to be seen. The rear needed 2 8mm bolts tightened a little bit but other then that all U joints are tight with no play.
How ever when I turn the drive shaft I get about half an inch of play in the rear diff and the transfer case before you hear the drive train get stopped by the gears. Both the diff and the transfer case make the clank noise of metal hitting metal.
I have recently changed the fluids on both of these and the fluids looked great and without chunks of metal. No leaks can be seen anywhere and the fluids on both are just above the bottom portion of the drain hole.
I used Mercon 5 in the transfer case (Recommended as the fluid to use) and Valvoline 85/95 gear oil in the rear diff.
Is this normal?
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Posting Guru
Joined: Apr 2009
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From: Northern Idaho
But isn't the spline between the rear diff and the transfer case? The play seems to be in the rear diff and some in the transfer case as well.
I'm not really sure where the spline is.
I'm not really sure where the spline is.
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From: Milroy, PA
Does your pinion on the front of the differential have any up and down play? Another couple things, What is your trucks cab/bed/axle configuration? (ie. ex cab, short bed, single rear wheel) Does your truck have a locker in the rear axle, or limited slip, or is it open differential?
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From: Northern Idaho
I don't know the configuration of the differential but my truck is a 99 f250 extended cab 4 door long box 4 wheel drive.
Maybe I should go to ford and get the 75w-140 synth and replace the 85/95 that napa recommended that I put in it.
Maybe I should go to ford and get the 75w-140 synth and replace the 85/95 that napa recommended that I put in it.
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Joined: Nov 2007
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From: Payson, AZ
Valvoline has a 75/140 Syn Power that already has friction modifer in it for limited slip diffs. That is what I am using and it works great. If your rear diff tag has 3L73 on it that means it is a 3:73 ratio limited slip. If it has 3 73 and no L it does not have limited slip.
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From: No.Va.
The movement (turning) of the drive shaft you are feeling is the backlash in the rear. If everything else is tight,u-joints (check 90* ea.way),no lateral play in the pinion, 1/2" sounds about right.
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From: Northern Idaho
I just took a look at the tags on the truck and if I had read the tags I would have seen the tag that said 75-140 Synth Only
I'll have to change the fluid again this week.
Also I found another tag that means crap to me atm but maybe you guys can enlighten me.
S 406 C
7310 5 8H18
I'll have to change the fluid again this week.
Also I found another tag that means crap to me atm but maybe you guys can enlighten me.
S 406 C
7310 5 8H18
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Posting Guru
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From: Northern Idaho
Post Fiend
Joined: Nov 2007
Posts: 9,549
Likes: 14
From: Payson, AZ
I just took a look at the tags on the truck and if I had read the tags I would have seen the tag that said 75-140 Synth Only
I'll have to change the fluid again this week.
Also I found another tag that means crap to me atm but maybe you guys can enlighten me.
S 406 C
7310 5 8H18
I'll have to change the fluid again this week.
Also I found another tag that means crap to me atm but maybe you guys can enlighten me.
S 406 C
7310 5 8H18
Below is how the codes are deciphered. It will take the mystery out of it.
The codes on the rear differential tag on my truck are :
S409B
3L73 102 8C11
The break down of these codes:
S409B:
S = Sterling Differential
409 = Print Number (Model Number)
B = Revision Identifier (Change in Design)
3L73:
3L73 = 3.73 Ratio
L = Limited Slip
Absence of L = Open Differential.
A 3.73 geared limited slip axle would be marked as : 3L73.
An open differential would show 3(space)73.
102 denotes the ring gear size. 10.25 inches. 105 would be 10.5 inches
8C11 is the build date.
8 = year of manufacture. In this case it means 1998.
C = month of manufacture. A= January, L= December so C= March
11 = day of manufacture. So My differential was manufactured on March 11, 1998
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Posting Guru
Joined: Apr 2009
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From: Northern Idaho
Well I took another look and the only thing extra I saw was a "."
S 406 C
. 73 10 5 8H18
Also, there was a space between the 73 and 10, sorry, my mistake but I don't think I have limitted slip
S 406 C
. 73 10 5 8H18
Also, there was a space between the 73 and 10, sorry, my mistake but I don't think I have limitted slip
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Posting Guru
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From: Northern Idaho