XK140 Rear axle or bearing "tension"?

XK
#1

Not sure if I’m encountering a problem or just normal behavior!

I’m doing a brake inspection plus clean and adjust on my XK140, she sat for @ 2 or 3 years before coming to my garage…

Started with the right rear… undid hand-brake, removed knock-off wheel and brake cover, removed brake shoes, cleaned everything, ensured adjuster works properly and freely and that cylinder slides freely in the back plate slot. Reassembled… and this is where the mystery comes in…
Before disassembly there was some “drag” when rotating the wheel (Car on stands, trany in neutral, handbrake off), thought it was likely sticking adjuster etc due to age and build up of dirt, hence the strip, clean, rebuild. But after reassembly, with the brake pads at minimum adjustment ie way away fro the drum, there is still a lot of drag when turning the wheel by hand… definitely not “spinning” it to center the pads etc. I assume at this point that the drag is coming from either the bearings or the rear axle… there is no apparent noise, no slop or freeplay… maybe this is normal tension from the differential?

Thoughts appreciated!

#2

Remove the drums on both sides and see how the hubs turn. They will turn in opposite directions if the driveshaft does not turn, and it usually doesn’t. There will be some amount of resistance due to the 4 spider gears turning in the differential.
Then you have to center the brake shoes, which is usually a matter of trying the drums once or twice and tapping the shoes around a bit.

#3

That is different when you have a LSD, like I have.
In that case both hub will turn in the same direction.

#4

Hi Rob, all four wheels are off the ground, both rear brake drums removed. When turning either left or right rear hub the driveshaft rotates, not the opposite side hub. There is enough “tension” or “drag” on both rear hubs that I cannot turn the hubs with one hand, I have to get a solid two-handed grip on the hub to get it to turn. Even with a wheel and tire mounted on either hub it takes both hands and solid effort to turn the wheel. This seems excessively firm to me, from my past experiences (20+ years ago so memory may be fooling me!) Doing rear brake adjustments mostly on Triumphs, I could rotate the rear wheel easily with one hand, definitely feeling some drag when compared to a front wheel, but not this much. This is my first experience with a solid axle Salisbury design maybe more drag is normal??

#5

Sounds like certainly a contrast with one I have here. I can turn either hub with one finger. With one, just the driveshaft flange turns. When I turn the other, both the driveshaft and the opposite hub turn, but if I hold either one the other turns.
Is yours by any chance a limited slip differential? They were optional on XK150 and could have been put on a 140 at any time.
Otherwise it sounds like you have some kind of problem in the diff.
My first guess would be pinion shaft too tight.
What’s the history? Was it restored by an unknown shop?

#6

Hi Rob, thanks for your insights, gives me something to think about!
Who knows if the rear axle is original? How many of these cars have made it this far without some parts swapping around? Somewhere along the way my C Type Head got replaced with a 120 SE head, I doubt it was done because someone wanted the C head, more likely because head repairs where needed and a swap was easiest!
The diff housing does have some markings on it… E53 855 under the “nose” and L9 raised on the front bottom left. Also some markings on the back right top and bottom but I can’t make then out.
In any event, the next step for me is to grease the hubs (along with everything else on the car) I doubt this has been done in a very long time… so maybe some fresh grease and a little driving will sort it out?!?
By the way, the service manual advises to not over grease, and says there is a bleed hole on the axle casing to indicate when sufficient lubricant has been applied… I have scraped and cleaned both sides and haven’t found such a hole.
I recall reading somewhere else in the manual to grease until the grease shows behind the hub nut and washer… I’ve put in 10 or so strokes on each side with no sign of grease anywhere but I don’t want to over do it and have it end up in the brakes… I guess it’s going to be a process of adding a little grease, driving for a bit, reassess, grease some more etc!

#7

Have you checked axle end float? It is quite easy to do with car raised. You simply wedge one side’s axle flange(the part with the five studs or the splines for wire wheeled cars) out away from the brake backing plate, then check end float at the OTHER axle. Should be about 8 thou.
Looks like you have already greased the bearing(s) so this will make it tougher the feel end float.

#8

Here is the hub grease vent hole.

grease vent hole
grease vent hole1920×2560 1.17 MB

#9

It’s probably clogged on his…IIRC, an eight inch drill bit cleared mine.

#10

Perfect thanks! Picture is worth a 1000 words, found it, took another 10 pumps to get any grease out of the hole, same for the other side, maybe things will loosen up now?
Now onto the last brake assembly for clean and inspection, looks like I’m replacing a steering gaiter while I’m here!

1610138448167871789331
16101384481678717893312160×3840 1.67 MB

Also searching for the fan bearing grease nipple as per the service manual… Dont see one so far… Any hints?

#11

I think Lee meant an eighth inch (1/8") bit. :grin:
The original 120 pump had a grease fitting, but my 1960’s replacement with 140 style bearing shaft does not, and I think your 140 pump would not have one, they were greased for life.

#12

I KNEW I shouldn’t have used such a big-ass drill bit!

#13

Of course, the water pump! Just installed a new one, no grease fitting on it! Thanks again