mk1-forum.net

The plan to slot the differential case for the washer tabs went ok...then I tried fitting the washers.
I don't know if castings this bad are typical but one side had substantially more material than the other - enough so that one of the washers couldn't seat. They sort of tried fixing it by adding a chamfer but there was only enough material to chamfer on half of the diameter. So my choices were down to adding more clearance with a file (too much manual work), die grinder (too much mess), or lathe (always the right choice!) After a few minutes of careful turning, both washers fit nicely and I was able to begin work on the stub shaft bushings.

One of the worn bushings fell out when I removed the shaft. The other I removed most of in the lathe then used a pick and hammer to work the thin remaining part out of the bore. I didn't have a 1.030" reamer and wasn't in the mood to make one so once again it was back into the lathe.

Next step will be to clean everything, reassemble with a new pin, new planet gears, new thrust washers, new diff bearings, etc and hopefully never have to deal with this one again.

Hi, A little tips on the torque setting of the 6 crown wheel bolts, being stretched (using used bolts)and finally shear happened couple of times during our diff rebuild, I wonder the 60 ft/lb given in Haynes and BMC manual is not correct, you can find 48 lb/ft in the Metro( diff rebuild )Haynes manual, which is more reasonable in accordance to the size of bolts used.
ARP recommneded only 50 lb/ft for their high grade LSD bolts.
Its is only my personal suggestion, hope it helps!

Al

That's good sound advice 970S. Those figures have been raised here before. I used what I called '.....my gut feeling...' when I did mine last time. Next time I think I will use the lowest torque figure and wire lock.

The tools used to get the drip rail radiuses correct are just brilliant

970s wrote: ↑Fri Aug 12, 2022 5:23 am Hi, A little tips on the torque setting of the 6 crown wheel bolts, being stretched (using used bolts)and finally shear happened couple of times during our diff rebuild, I wonder the 60 ft/lb given in Haynes and BMC manual is not correct, you can find 48 lb/ft in the Metro( diff rebuild )Haynes manual, which is more reasonable in accordance to the size of bolts used.
ARP recommneded only 50 lb/ft for their high grade LSD bolts.
Its is only my personal suggestion, hope it helps!

Al

Good advice and I had a similar experience doing a LSD swap on a Sprite differential. The previous owner had replaced the factory bolts with grade 8 bolts and I wasn't thinking - snapped one off in the ring gear. It looks like Sprites and Minis use the same ATA7043 bolts.

Funny thing is I've done a few LSD swaps on Sprite diffs and re-torqued used stock bolts to 60 ft-lbs without issue but it sounds like I've gotten lucky. I made the dangerous assumption that BMC specified a higher strength alloy for these bolts to get to that torque number but that assumption may be totally wrong.

Peter Laidler wrote: ↑Fri Aug 12, 2022 9:22 am Next time I think I will use the lowest torque figure and wire lock.

The tools used to get the drip rail radiuses correct are just brilliant

I think I'm going this plan. I am not a fan of tab washers for anything in the powertrain. I've done just torque and threadlocker previously but I like the safety wire idea.

(Also thanks - more drip rail repairs coming soon)

In the tech pages of the forum you'll find that our old pal Bart Theelan and Nick Rogers have done a few pages on the comparative BL/BMC fixtures and fittings/Nuts, bolts and washers. It makes VERY interesting reading for tech nerds like me.

However, it doesn't mention the high tensile bolts so far as I can see. But some bolts that I consider SHOULD be Hi tensile, clearly aren't!

Good reading

The best place for Fastener decode info is on the Main site.

https://mk1-performance-conversions.co. ... teners.pdf

You're right! Copied and logged in my garage file

A bit more progress since August - got the differential reassembled and reinstalled in the transmission, replaced the output yoke bushings, got a good used set of output yokes, and generally got the transmission reassembled as much as possible without having an engine to bolt it to. I bolted the shift level to the housing, ran it through the gears, and everything felt good so calling it good enough for now. Bagged and on the shelf!

Back to rust repair - I have been mulling over how to tackle the roof gutters since 2015. I really appreciate finding previous handy work - nice use of foam to hold body filler in place while it set! The plan for the rear gutter worked out okay but only because the contour was fairly simple. I started off making a MDF former for the side gutter on the driver side and was able to get something usable but it being curved in two directions made it a colossal pain. You don't appreciate how much it curves upwards near the side seam until you are trying to make an angled piece match the curve.

It took less time to drive to Harbor Freight, buy a metal stretcher/shrinker set, drive home, and make the even more complicated front driver side repair (money well spent!) These have been a huge time saver and I wish I would have bought them years ago.

Very impressive result

What brilliant work!

Following this with interest and really impressed.

Roof profiles are black belt stuff!

Thanks again - still slowly making progress.

I am calling the gutter repair good enough for the time being. I have to grind the welds and hammer everything back into shape but that is for later.

Next - addressing the front subframe mount. The previous owner bought many replacement panels but never installed them. Included in the parts pile was a rubber mount front fascia. Since it was basically free, I made the decision back in 2015 to use it and added some spacers to get me through the build phase. Fast forward to 2023 and it is time to address this the correct way.

I started by making a fixture out of square tube and tack welding it to the mounting tabs. Next I removed the rubber mounting bracket and used them to design the new bracket and the MDF former.

Finally after some bending, hammering, and repeating, I had two new brackets.

A question before I weld them in place - is the area around the 3/8" mounting hole reinforced in any way or is it just the one layer of 16 gauge steel with a washer beneath the subframe bolt head?

No reinforcement needed

Thanks!

I got it wrapped up a few days ago. I'm calling it "better than it was".

Long story short - lots of hammering to finish gutter repair work followed by epoxy primer, filler, and more primer. I opted for single stage on the underside, engine compartment, and interior and a base/clear for the exterior. The doors should go on for one final time tomorrow!

That is all...

Just



Nicely done.