1975 differential half shaft end play
Thread Starter
Instructor
Joined: Mar 2013
Posts: 180
Likes: 21
From: Chesterfield Mo
1975 differential half shaft end play
My differential half shafts have .140 and .116 end play. See the videos. Is this too much for a car driven conservatively less than 2000 miles a year? Rear suspension is out of car being rebuilt. Car shows 50000 miles on odometer. I can see by silicone sealer that someone has been into diff in the past. Was trying to avoid taking diff out but see mission creep happening. What should I do?
Le Mans Master
Joined: Dec 2006
Posts: 8,837
Likes: 1,028
My differential half shafts have .140 and .116 end play. See the videos. Is this too much for a car driven conservatively less than 2000 miles a year? Rear suspension is out of car being rebuilt. Car shows 50000 miles on odometer. I can see by silicone sealer that someone has been into diff in the past. Was trying to avoid taking diff out but see mission creep happening. What should I do?
Race Director
Joined: Apr 2009
Posts: 19,294
Likes: 2,754
From: Charlotte NC
I will say that the 'beginning of the end' has begun.
IF the wear can get so bad that the dust cone that is pressed onto the yoke can actually eat into your differential housing and damage the seal and also teh land where the seal gets pressed into. I have seen it...but I doubt you are at that point yet...BUT...it is NOT getting any better.
What also can happen which may require you to change out your strut rods to adjustable ones is that the side yoke gets so short..that the factory concentric bolts and strut rods (which are a fixed length)...that your concentric bolt for your strut rod adjustment is now out of its range and you can not set/adjust your camber.
IF you do replace your side yokes....do yourself HUGE BIG FAVOR and also remove and you will more than likely need to replace the pinion shaft which is the rod shaft that the side yokes wear against.
Putting in new fresh side yokes on a worn pinion shaft is ludicrous.
And also....take a very close look at the tip of the long bolt your removed to get the pinion shaft out. I have seen them at the tip shows a crack or bend. I often times put a new one in to be on the safe side if for any reason I do not like how it looks.
DUB
IF the wear can get so bad that the dust cone that is pressed onto the yoke can actually eat into your differential housing and damage the seal and also teh land where the seal gets pressed into. I have seen it...but I doubt you are at that point yet...BUT...it is NOT getting any better.
What also can happen which may require you to change out your strut rods to adjustable ones is that the side yoke gets so short..that the factory concentric bolts and strut rods (which are a fixed length)...that your concentric bolt for your strut rod adjustment is now out of its range and you can not set/adjust your camber.
IF you do replace your side yokes....do yourself HUGE BIG FAVOR and also remove and you will more than likely need to replace the pinion shaft which is the rod shaft that the side yokes wear against.
Putting in new fresh side yokes on a worn pinion shaft is ludicrous.
And also....take a very close look at the tip of the long bolt your removed to get the pinion shaft out. I have seen them at the tip shows a crack or bend. I often times put a new one in to be on the safe side if for any reason I do not like how it looks.
DUB
Le Mans Master
Joined: Nov 2003
Posts: 5,772
Likes: 694
From: Maryland
St. Jude Donor '05, '09, '15
It looks excessive to me. That said I don't think it leave you standing somewhere....yet. But remember the half-shafts are the upper link of your suspension. So any play from stub axles translates into suspension play. I mention this because your are having the rear suspension redone. If you don't fix it I suspect you will find excessive in/out motion from the top of the wheels even after the suspension refresh. I also would prepare yourself for a diff rebuild. You will probably find stub-axles ends worn and worn posi plates. Will you be happy with a partial fix? JMO
Tom
Tom
Melting Slicks
Joined: May 2002
Posts: 2,225
Likes: 44
From: Penticton B.C. Canada
You need to change your stub yokes. It's quite easy really, I did mine last off season. I had my diff on the ground in less than 2 hrs. Mount the diff on an engine stand to make life easy. If you don't have an engine stand somebody you know does and will be too happy to lend it out to get it out of the way for while. The only special tool I had to buy was to upgrade my Snap Ring Pliers :-)
Buy Lone Star yokes. Don't buy them from Duntov.
Buy Lone Star yokes. Don't buy them from Duntov.
Racer
Joined: Aug 2003
Posts: 466
Likes: 18
From: Belgium /
If you buy new yokes measure them before install, I bought new yokes from lone star and they were shorter than my Old worn yokes, so QC is very bad.
They did send me replacements but still shouldn't happen with new parts.
They did send me replacements but still shouldn't happen with new parts.
Melting Slicks
Joined: May 2002
Posts: 2,225
Likes: 44
From: Penticton B.C. Canada
Lone Star is the preferred supplier of Gary Ramadei [google him] and other high quality re-builders.
Who's yokes do you use Dub?
If your yokes are to a point that they need to be replaced there is no measuring required.
It doesn't hurt to measure after assembly tho to make sure all is in spec. The re builders usually get them tighter of course.
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Drifting
Joined: Mar 2011
Posts: 1,886
Likes: 9
When my car had about 110,000 miles, I had the diff rebuilt. Among other things, the end play of the side yokes was excessive. After the rebuilder put in fresh posi clutch packs, the end play was perfect. No further action was required.
Racer
Joined: Aug 2003
Posts: 466
Likes: 18
From: Belgium /
That is interesting, how long ago? It is rumored that about 10 years ago that LoneStar received a batch of yokes that were not hardened as the should have been.
Lone Star is the preferred supplier of Gary Ramadei [google him] and other high quality re-builders.
Who's yokes do you use Dub?
If your yokes are to a point that they need to be replaced there is no measuring required.
It doesn't hurt to measure after assembly tho to make sure all is in spec. The re builders usually get them tighter of course.
Lone Star is the preferred supplier of Gary Ramadei [google him] and other high quality re-builders.
Who's yokes do you use Dub?
If your yokes are to a point that they need to be replaced there is no measuring required.
It doesn't hurt to measure after assembly tho to make sure all is in spec. The re builders usually get them tighter of course.