Dana 18 shift rail seals

[51 CJ3]

I am following a thread on another forum. The poster says neither him nor the shop can get the called for seals into the holes for the shift rails. They are claiming a .050” difference between the size of the seal and the size of the hole. He has tried different seals from different vendors with the same results. I measured mine and the difference was around .016” for the SKF seal I bought to replace the Crown seal I ruined. I don’t think it would be possible to install a seal into a hole that is .050” smaller than the seal. Does anyone here have knowledge of front caps with different sized shift rail holes?

Thanks
Jeff

[bmorgil]

There is only one size used on the shift rails in the Dana model 18. The correct part number is A-974 or a National 472635.

[51 CJ3]

That part number comes up with a nice double lipped seal from SKF (6229) at NAPA. Which the guy tried along with the single lip Crown (CA2469) seal sold by KW and seals from other suppliers. I suggested maybe someone sleeved it or did some other repair but he says there is no evidence to support that. Apparently the bores are around .035” smaller than mine.

I bought the seal kit from KW and did a foolish thing. I tried to install both seals at the same time. I think it would have worked except the surface isn’t perpendicular to the holes. The result was one Crown and one SKF but no real issues installing them that weren’t self induced.

I was going to install the front cap this morning but realized what I took out of it was a mixed bag and I wanted the correct hardware. The only place I could find any information on the bolts was in the military manual which gave me a military part number that crossed to a 1” long 3/8x16 grade 5 bolt. A trip to the hardware store is in my near future (nothing open on Sundays here).

[bmorgil]

You never know what he could be doing or, if the information is correct. There never was any changes made to that shaft and seal from 1941 through 1972. I have not heard of such an issue in my experience. It is the same seal used in the Dana 20. It is used in Willys, IHC, Ford, GM vehicles and many off road equipment and Military vehicles. Same seal. I can guarantee you the assembly line would not have made a "one of" with a rare unknown seal.

[51 CJ3]

It had either been sleeved or had a seal come apart and left a sleeve.