13 replies to this topic

[Bobbins]

Hoping someone can help …

A few years ago I fitted a “MED Mpi Injection Ultra Light ST1” flywheel to my ‘98 1275 Mini, all good but now I’m doing a full engine rebuild so it needs to come off.

Knowing the trouble I had removing the original flywheel I’ve invested in a KAD heavy duty flywheel puller which is supplied with two sets of bolts to secure to the flywheel:

- 3 of M10 x 110mm (edited … M10 not M8!)
- 3 of 3/8 UNF X 125mm (5”)

Unfortunately neither set will screw into the flywheel, I’ve trial fitted a short 3/8 UNC bolt and it screws in, although a little loose for my liking. Before I speak to MED does anyone know what the size the 3 threaded holes are likely to be? I’d assumed they’d be the same as the original Mpi flywheel although in truth I don’t actually know what that would be, but my old puller bolts fitted fine … before I destroyed the puller!

Stu.

Edited by Bobbins, 07 November 2024 - 08:35 PM.

[nicklouse]

Pre Verto should be imperial. Verto Metric. M10

 

if UNC is going in I would say it has metric threads.

 

but check with MED.

Edited by nicklouse, 07 November 2024 - 08:32 PM.

[Bobbins]

Apologies Nick, I did mean M10 rather than M8! I would expect it to be M10 but don’t want to force anything.

Edited by Bobbins, 07 November 2024 - 08:34 PM.

[slidehammer]

Definitely check with MED, because if you use the wrong bolts and strip the fly wheel under load you are in a total world of pain. I would have thought they would be 1 of the 2 standard thread sizes used on the Mini. Also oil the main puller thread before use as it helps the force be transmitted to pulling rather than lost in friction when under strain.

[Bobbins]

I’ve emailed MED to confirm they’re M10.

[Icey]

I’ve got the same puller and the same flywheel, mine used M10 bolts without issue.

[Bobbins]

Update … I checked with MED and definitely M10. I had another go this afternoon and the uppermost threaded hole (with the flywheel locked) was still refusing to take an M10 bolt, but, I tried the other holes and the bolts went in fine! A worrying few moments but with some force the one I’d been previously working on did start to take the bolt and eventually screwed in fully home, phew!

The end result being that 10 minutes later the clutch assembly was off the crank … it took 3 days when I removed the original Rover Mpi flywheel. A massive thumbs up for the KAD puller.

[imack]

KAD puller is expensive, but a great piece of kit. In my experience, the flywheel doesn't fly across the garage when it comes off either, presumably because it's much more rigid and doesn't flex as much and store energy like ordinary pullers. Just a loud crack and the flywheels off.
I've managed to use it in situ too, with a piece of wood wedged between the inner wing and subframe to give a little more clearance. Have to use a 32mm ring spanner with a long bar on it on the puller bolt, no room to get a socket on the bolt.

Attached Files

•  Screenshot_20241109_195816_Gallery.jpg   42.03K   6 downloads
•  Screenshot_20241109_200142_Gallery.jpg   40.88K   6 downloads

Edited by imack, 09 November 2024 - 08:04 PM.

[mini-mad-mark]

The reason the flywheel doesn't fly off is a design feature of these good pullers - hard to explain in words and I don't actually have one to take a picture of  (but I have borrowed one) and basically the centre part that butts up to the end of the crank has a step up diameter that is larger than the bore of the flywheel (the cheap one is just a plain part that is smaller than the bore so the fly wheel can "fly" off - pun fully intended)

[imack]

I thought it was only the guessworks puller that had the step up to retain the flywheel, I'm certain my KAD one doesn't have that feature. I'm currently away on holiday but I'll check when I get home. Engine is coming out next week for a refresh, so I'll be using the puller.

[mini-mad-mark]

I just assumed it would be the same on all the "good" pullers but I've only seen one and not sure from whence it came so I guess I have commented incorrectly when generalising.

[Bobbins]

This is the KAD puller close up and it’s not wider than the end of the crank, no big bang when the flywheel released though …

Edited by Bobbins, 16 November 2024 - 03:31 PM.

[imack]

I think it's just the fact that the puller is ridged and doesn't bend and flex towards the flywheel as torque is applied to the puller main bolt. Mine just makes a loud "crack" sound and initially you think somethings broken. The flywheel barely moves but you find it's now loose on the taper.

[Bobbins]

I think it's just the fact that the puller is ridged and doesn't bend and flex towards the flywheel as torque is applied to the puller main bolt. Mine just makes a loud "crack" sound and initially you think somethings broken. The flywheel barely moves but you find it's now loose on the taper.

Yes I agree, I suspect it’s likely the energy absorbed by the cheap pullers (acting like a spring) that causes the almost explosive release when the flywheel lets go.