Excessive rear driveshaft endfloat?

[ChrisHeapy]

I pulled the hubs off the rear axle the other day to check the parking brake shoes (which were badly worn as it turns out). What worried me was the amount of 'free play' or endfloat in the driveshaft. It moves freely in and out by about 5mm or maybe more - like it was sliding on splines or something. This movement seems excessive to me but I can't see what's supposed to limit it. How much play should there be? It drives OK, but I'd rather not have the back wheels fall off driving down the road

Chris

 

[SteveVB]

Its OK

The shafts should move in and out a bit- 5mm doesnt seem excessive. The end of the axle inside the differential has a clip on it to keep the axle from seperating from the diff, and it is splined (31 of them) into the side gears of the diff.

If your worried about it, pulll the diff cover and take a look at the clips, and the side gears make sure they are not worn,
But to me it sounds OK .

 

[ChrisHeapy]

OK, thanks!

Can't figure those brake shoes though, there was just a sliver of metal remaining. Previous owner must have driven around with the parking brake on!

Chris

 

[Robert]

That is perfectly normal. I just went through that on my '97 4x4 Sport. I had a rattling noise coming from the rear so I got to looking at therear. I found that both of my wheels moved in and out very easily. I figured my wheel bearings were shot. When I took it to my local shop and explained what was happening, they took me around and showed me a couple of full-sized F-series trucks and a couple of Explorers, one older, one newer. The guy pushed on the rear of the vehicle which caused all of the vehicles to make a thumping noise as the axle slid back and forth. He explained the C-clip thing to me explaining that the Ford rear ends do have some play.

That wasn't the source of my noise however, the axle bearings were bad. They allowed my wheel to move up and down, which shouldn't happen. In and out is OK.

 

[yob_yeknom]

Originally posted by ChrisHeapy
OK, thanks!

Can't figure those brake shoes though, there was just a sliver of metal remaining. Previous owner must have driven around with the parking brake on!

Chris

Same thing with mine!

Here's a hint: If you take the time to pull off the diff cover and, go ahead and take the axle shafts loose. That way you can slide them out a little bit so it will be easier to change the e-brake shoes. Those things were a BI-@TCH to replace!!! No place between the wheel studs to get to the brakes, so you have to work behind there. VERY tedious work.
DO NOT pull them out far enough to let them come off the splines on the other end. You don't want to have to change rear end seals because that end had to hold up all the weight and made the seal out of round.
Good luck!

 

[ChrisHeapy]

Originally posted by yob_yeknom
Same thing with mine!

Here's a hint: If you take the time to pull off the diff cover and, go ahead and take the axle shafts loose. That way you can slide them out a little bit so it will be easier to change the e-brake shoes....

Did this job over the weekend, but without any spare diff oil to hand decided not to pull the shafts. I found the job quite easy though, you had me worried there for a minute! I was puzzled how to go about getting the new shoes in, until I figured how to use 3 screwdrivers together to force them apart at the bottom to get the screw adjuster in.

If you slip the top end of both shoes in first (with rear spring in place), then fit the remaining 2 springs, then put a screwdriver through each where the retaining pins go to hold them in place against the backing plate. Then it's easy to use a third screwdriver at the bottom end to force them apart and slip the adjuster in place. The second side only took a couple minutes.

Chris

 

[Kampy]

Axle endplay

Just a tip for you guys, keep an eye on that end play, should be around an 1/8" and it should be nearly equal on both sides. 5mm is about 1/5", I would look for something going wrong, especially if you have a L/S diff. Heres what happens with the L/S diff.

As the clutch packs wear they allow the side gears to go deeper into the case which changes the contact pattern on the side gears and spiders. they start wearing funny and eventually wear the crown of the teeth off and snap, no more go. Trust me, just fixed one this weekend that it happened to.

Total wear from the clutch thats laying beside the gear was only about .070 , not much but it was enough to let the gear start wearing in an irregular pattern. It starts wearing funny on the affected side gear and the bad pattern is transfered to the spiders and then to the other side gear. Look for pitting or galling on the spiders.

Here is a pic of what the parts look like after it decides it don't want to play anymore.

The easy way to fix this is fix it before it breaks, This rearend had about 120K on it. If the L/S doesn't work well anymore put new clutches in it to get the clearance back in specs.

Hope this helps.