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These are various house, car, and bike projects i've done. And more!

New: TR6 work log, a running tally of work on the car, and the future todo list.

Front hub rebuild

Posted on July 30, 2019

One known weak area in the TR6 design is the front spindles. They aren't weak enough to be a safety issue, but they do flex a bit given enough lateral force. The flex is enough to push the brake pads away from the disk, so the next push on the brake pedal is soft, because part of the travel is pushing the pads back in place.

I don't plan to autocross or otherwise drive the car all that hard, but in a parking lot or even getting in and out of my driveway, i've noticed the soft brake pedal, and it's disconcerting. There are 2 ways to fix the issue; either replace the spindle with a heavier version, or add a spacer between the bearings to make the unit stiffer. Since the existing stuff is in good shape I opted for the spacer version, both for the cost and simpler install - no pounding out the old spindle.

The existing bearings seemed pretty smooth, but a new set isn't terribly expensive, and it seemed worth replacing the bearings and seals while i had the whole thing apart anyway. 

bare front hub

Here's one of the hubs, cleaned up and ready to knock out the inner race. There are slots behind the race that makes it easy to connect with a punch through from the other side.

These are the parts with the bearing kit (bearings, felt seal and grease), and the spacer kit (tapered spacer and set of sized shims). 

front hub rebuild parts

The micrometer was handy to figure out which shim sizes were which. The method is to install the inner bearing, hub, spacer, shim, and outer bearing, then D washer and nut. Tighten the nut to spec and check for wiggle. Repeat with smaller shims until the hub spins smooth but with no lateral wiggle. The seal is left out for an accurate measure, since the seal will compress on final installation anyway.

The first wheel went great. When i got to the second hub, the outer race was flopping around in the hub. Apparently at some point in the past the outer bearing had spun, but it was just regreased and assembled again. It did roll, but not an ideal state for a critical bearing.

Big thanks to MN Triumphs club for help on what could have been an expensive delay. I discovered the problem on a Saturday morning, and after a quick look at the usual online suppliers, i emailed the club to see if anyone had a spare. I got an answer and a replacement hub from a fellow member before dinner. 

Back at reassembly, a side complaint about the quality of replacement parts. This shows the felt seal shell that i pulled out of a hub compared to one of the new ones from the bearing kit.

oil seal comparison

The shell at the right is so thin that it started collapsing when i tried to tap it into the hub shell. Happily, even though i bought them both at the same time from the same supplier, the bearing kits were weirdly inconsistent, and the other seal was much closer to the thick, older design.

Another odd inconsistency with the bearing kits: both came with bearing grease in identical packets, but one was clear and the other was very blue.

grease colors

That felt seal gets soaked in oil then squeezed out in a vise before installation. I found out the hard way that it takes a good squeeze to get the extra oil out: it's disheartening to get everything snugged down with a nice smooth spin only to see oil dripping out from the back of the rotor.

In the end, it was an easy 1-day job that took me about 4 days to complete. The hubs feel snug and smooth. I just need to finish my dashboard refinishing to get it on the road for a good test.

finished front hub

As long as i had the front wheels off, i replaced 2 body mounts between the inner fenders and frame. I traced down a front noise to one of these mounts being loose, which wasn't surprising when i realized that what had been rubber pads were now crumbling disks of just the canvas reinforcement.

body mount spacers

New mounting stack on the left, old on the right. The other side of the car was missing the middle aluminum spacer, which is why it was so clunky.