2008 Dynatrac rear full float hub seals leak

[roadtrip]

This is the second time I had to shorten a road trip due to leaks developing at the rear hub seals. I had a reputable mechanic replace the seals the first time but here I am 15k miles later with another leaky seal. I did some web searching to see what could be causing the problem so I can have the mechanic check during repair.

A few questions. The last mechanic replaced the seal with a Napa 28426. The Dynatrac parts list I got with my SMB purchase calls for a DA60-1175-A which I have not been able to cross ref to any other mfgr part no. It also lists what I believe is a Timken part no. 2081. Should I go with the Timken over a Napa replacement?

I plan to have the mechanic inspect the wheel bearings for wear. I also have the Timken part nos. for the bearings in case they need replacement. I read that heat build up could contribute to seal failure so maybe that is the cause.

Should the wheel bearings be packed when put back together? I read that even though diff lube reaches the bearings they should still be packed with wheel bearing grease. If so, any recommendations for type of grease? I've been running Amsoil Severe Gear 75-140 in the diff if that is a consideration.

I plan to have the mechanic check for a clogged diff breather because I read that can also be a cause of leaky seals.

I noticed a bit of seepage from where the drive axle shaft bolts to the hub (8 bolts). Should some sort of gasket material be used to prevent this? Or perhaps it just was not tightened enough. Are there torque specs for the 8 bolts?

Any other suggestions for what could be causing the seals to leak? Any links to info on my particular rear end (2008 Ford limited slip converted to full float by Dynatrac) is appreciated. Or if someone knows of a knowledgeable contact at Dynatrac and has their number to share.

Thanks!

[CLMorgan]

I'd go with Timken.

[ShuttlePilot]

Greetings Roadtrip, This April I talked to Dynatrac about ball joints and a steering rod for my front axle. I just called the phone number off their website. Steve at Dynatrac seemed to be the bearded man who knows their products off the top of his head. I also spoke with Collin who admitted he was new there but might be up to speed by now.

I would also go with the Timken seals if I had the choice. I think that's what I used for my front diff seals a while back. And just a few thoughts on seals. Seals can be damaged by inserting the axles with the weight of the axle sliding on the seal creating a flat spot or a crease. I'm not bashing your mechanic, but it can happen if say in a hurry to get it done. Perhaps not deal breaker but I always thoroughly clean the axle where the seal rides (sand is bad) and put a thin (very thin) layer of grease around the axle where the seal rides. Finaly, make sure it's the correct seal by looking at the number on the seal. Wrong parts can be put back in right boxes. Kind of far fetched but if everything is checking out fine and there is oil on the ground there is something that still not right.

I'd call Dynatrac and see what advice they have first.
-Eric

[roadtrip]

Thanks for the replies.

This is what I found out from research and calling Dynatrac customer service.

Dynatrac recommends Lube spec GL5 85-140 for warm climate.
They do not add any friction modifier additive.
Pack inner and outer wheel bearings with disc brake wheel bearing grease.

Torque Specs for Dynatrac FF Conversion:

Differential cover bolts- 35 (lb-ft)
Wheel lug nuts- 120 (lb-ft)
Rear axle shaft to full floating hub bolts- 115 (lb-ft)

REAR wheel-bearing spindle adjuster (inner) nut:
Step 1: To seat, torque nut to 50 (lb-ft) while spinning hub.
Step 2: Back off ~1/8th turn.
Coat locking washer with grease and add.
Rear wheel-bearing lock (outer) nut- 70 (lb-ft)
Lock the outer nut. There should be no more than .001” of end play when finished.