Drive Members and Hubs

[Paul]

I've been following the thread in the Tech Archive to convert my 200Tdi drum brake Salisbury to discs. I accumulated 300tdi calipers and mounts together with (what I was told were) early 110 front hubs.

After assembling the 110 front hubs with bearings and new 300tdi rear discs, then installing the caliper mounts using a 5mm spacer just like the Tech Archive thread, I tried to put the whole lot on, only to find that the caliper wouldn't line up with the disc. It was out about 5mm - exactly the width of the spacer I had made up. No problem I thought, I just pulled it all apart again, and this time put it back together without the spacer. Everything lined up perfectly. The disc was in the middle of the caliper and after swappinmg the seal track spacer for a spacer from the front of a 200tdi, the bearings did up perfectly too.

Whilst I was a bit curious that I didn't need the spacers for the caliper mounts, I wasn't letting it worry me since everything fitted so well. Until...the drive member bolts are different. My 200tdi has 10mm bolts for the drive members, and these early hubs are 3/8 UNF. OK, so that's not such a big problem, the local bolt store had the right bolts in stock so it only cost me an hour or so. What is a problem however, is that even with the right bolts I can't ge my drive members to fit. I'm using Maxidrive 5806 drive members and it seems the spacing of the bolt holes on these early hubs is just slightly different to the metric hubs. If I get one bolt in, none of the others line up properly, even with the looser fit of the 3/8 bolts in the holes meant for 10mm bolts on the drive memmbers? Can anyone confirm that they did change the pattern for the bolts, and did it happen when the bolts went from imperial to metric?

Assuming that is the case, I guess my options are to either:

a) Enlarge the bolt holes on the Maxidrive drive members to get them to line up (definitely not my 1st preference);

b) Get a pair of early drive members to suit the hubs, or some aftermarket replacements (but I'm not keen on giving up the Maxidrive units I have);

or,

c) Try to find some early hubs after the change to metric bolts.

I think c) above seems to be the best option, but I suspect that the metric bolts started around 200tdi era, and finding parts for a 200tdi in Australia is problematic at the best of times.

Anyone have any better ideas?

[kingrat]

Sounds like the pitch centre diameter is different. The 3/8 bolt will probably fit with the RRC drive flange. I had a similar problem with the rover disk braked axle I fitted to my old 90. I think its to do with the axle you have fitted being one of the fused drive flange/half shaft ones so its either buy fused DF/HS or get RRC flanges.

HTH

Paul

[LR90]

Paul, I've had just the same issue putting an early (imperial and smaller pcd) disk brake axle on the rear of mine with later (metric) drive flanges. In my case I modified the drive flanges but at some point will swap the hubs to metric.

[Retroanaconda]

If it were a Rover back axle as per 90s/Discos/etc then one could just swap over one's hubs?

[Paul]

OK to finish off this thread, I ended up tracking down a pair of 200tdi era front hubs exactly the same as those on my vehicle i.e., wide bearing spacing and metric drive member bolts/pcd. I assume the hub bearing spacing changed late in the 200tdi era when the brakes went to discs all round, ventilated fronts and the railko bushes were replaced with taper bearings.

Anyway, the outcome is that on my vehicle the matching front hubs fitted on the rear with 300tdi era rear discs, calipers and caliper mounts, all without the need for any sort of spacers for the caliper mounts, even though I already had them made up. The only change from the drum brake "standard" was the deletion of the seal track spacer (FRC8227)and replacement with the thinner spacer from the front setup (R217352). Because the seal track spacer sits on a slight lip on the stub axle, I needed to grind out the hole in the front spacer a little, otherwise it caught on the lip when doing up the bearing lock nuts and prevented the correct adjustment. Instead of R217352 you could use FTC3185 which is the spacer from the front and rear of the later hubs, but this also needs the same slight grinding out, and needs further work on its outside diameter because in this setup it will foul on the inside of the drive members. Not using FRC8227 anymore meant that the outer seal can't be used, but I'd thrown that away to get my bearings oil lubricated years ago.

Finally, an added bonus was that the existing brake lines for the drum brakes also comfortably reached the disc calipers. Mine were still in very good condition and were easily bent to align with the new positions, even though I had the correct brake lines on hand.