Project Car / Motorbike thread. Let's see 'em.

Haakon

Keeps on digging
What would you do?

Pilot bearing bore in the crank is slightly out of spec, so the bearing can be (just) slid and pulled out with a finger.

By the time ive pulled the crank out to have the bearing recess machined out to take a bearing 2mm larger diameter (and put new bearing shells and rod bolts in, replaced the timing kits thats 60% of the way through its life - stuff you may as well/should renew if its off...) Id be up for about $500.

Or - distress the bearing recess a bit with a punch and use some Loctite 680 retaining fluid and cross my fingers...
 

beeb

Dr. Beebenson, PhD HA, ST, Offset (hons)
What would you do?

Pilot bearing bore in the crank is slightly out of spec, so the bearing can be (just) slid and pulled out with a finger.

By the time ive pulled the crank out to have the bearing recess machined out to take a bearing 2mm larger diameter (and put new bearing shells and rod bolts in, replaced the timing kits thats 60% of the way through its life - stuff you may as well/should renew if its off...) Id be up for about $500.

Or - distress the bearing recess a bit with a punch and use some Loctite 680 retaining fluid and cross my fingers...
The later, and don't worry about it unless it becomes a problem later (unlikely).
 

Flow-Rider

Burner
What would you do?

Pilot bearing bore in the crank is slightly out of spec, so the bearing can be (just) slid and pulled out with a finger.

By the time ive pulled the crank out to have the bearing recess machined out to take a bearing 2mm larger diameter (and put new bearing shells and rod bolts in, replaced the timing kits thats 60% of the way through its life - stuff you may as well/should renew if its off...) Id be up for about $500.

Or - distress the bearing recess a bit with a punch and use some Loctite 680 retaining fluid and cross my fingers...
Renno quality sheesh.
Was the old spigot bearing tight in the bore of the crank?

If it's a car you're going to thrash, it's only going to get worse and cause other issues eventually like premature wear on the gearbox input shaft bearings, leaking gear box seals and binding of clutch centres on the input splines. Even if you witness mark the contact surface they usually come loose again I've found.
 

Haakon

Keeps on digging
Renno quality sheesh.
Was the old spigot bearing tight in the bore of the crank?

If it's a car you're going to thrash, it's only going to get worse and cause other issues eventually like premature wear on the gearbox input shaft bearings, leaking gear box seals and binding of clutch centres on the input splines. Even if you witness mark the contact surface they usually come loose again I've found.
The engine has never had a pilot bearing fitted before because it was attached to an automatic - so 14 years of light surface corrosion and then me stupidly running a bit of emery paper over it to clean it up has taken "just" enough material off to make it not an interference fit.
 

Haakon

Keeps on digging
What if you witness the shit out of it?
Flow is correct that it will eventually beat the ridges back down and put it back at square one. The only "proper" repair is to machine it out for a larger bearing or replace the crank...

But. Maybe the loctite keeps it tight enough that it doesn't move around, and maybe I stake the end of the recess the keep it from coming out if it does come loose...

Super annoying. Dont really want to pull the crank and there is certainly no need otherwise - its a really nice low kms engine.
 

Haakon

Keeps on digging
Distress is haakon speak for witness.

@Haakon
Get yourself a dirty big hammer, belt in some punch marks and whack a metric shitload of 620 in there. Clean everything really really well and you’ll need a press and some heat to get it apart.
distress the surface with a punch, creating a bunch of witness marks from the punch? something like that...

I don't think its a very hard working bearing, its not a super tight fit on the input shaft nose at least, and the input shaft is solid and with a big front bearing - it would be a floating input shaft otherwise i suspect.

The Murphy is strong in this one. I even had a good crank in the other engine that i then accidentally left out in the rain when i got distracted by crashing my bike, so thats stuffed now.
 

Ultra Lord

Hurts. Requires Money. And is nerdy.
The engine has never had a pilot bearing fitted before because it was attached to an automatic - so 14 years of light surface corrosion and then me stupidly running a bit of emery paper over it to clean it up has taken "just" enough material off to make it not an interference fit.
Give yourself an uppercut you peanut head. Keep emery well the fuck away from interference fit surfaces. Scotch pad will do the trick usually, if it doesn’t it’s too far gone anyway.

But, nothing a bunch of loctite and a centre punch won’t fix.
Everything fails eventually, get it machined to the larger bearing when the rest of those things you listed need replacing.
 

Flow-Rider

Burner
Yeah, PITA, I wonder if you can try some other branded bearings that might be a bit tighter with tolerances. Pretty much all the ones I've patched up over the years have come back when the next clutch was due flopping around.
 

Haakon

Keeps on digging
Yeah, PITA, I wonder if you can try some other branded bearings that might be a bit tighter with tolerances. Pretty much all the ones I've patched up over the years have come back when the next clutch was due flopping around.
The OEM one out of the old crank is an SNR, and i have a new SKF and theyre identical. And a japanese one from eBay due next week to try as well.

Did your patch jobs include loctite bearing retainer? If I get the life of the clutch out of it ill be happy... If the car is still around then i might do a turbo engine transplant anyway :) Or use a turbo engine with an Eaton...
 
Last edited:

Flow-Rider

Burner
The OEM one out of the old crank is an SNR, and i have a new SKF and theyre identical. And a japanese one from eBay due next week to try as well.

Did your patch jobs include loctite bearing retainer? If I get the life of the clutch out of it ill be happy... If the car is still around then i might do a turbo engine transplant anyway :) Or use a turbo engine with an Eaton...
Yeah, we used to sub-let to auto sparkies in the same building and they would buy the bearing retaining loctite by the boxes.
 

Dales Cannon

lightbrain about 4pm
Staff member
Primer and loctite should be fine depending how much slop there is. Loctite gives you a guide for gap filling, be wsry of dimpling the crank, if you push the bearing off centre life will cease as you know it.
 

SummitFever

Eats Squid
I have never heard of this 'dimpling' of which is being spoken of so can only assume it is some next level hillbilly shit that even a country boy like myself has not heard of.

Like @Dales says, consult the loctite bearing retaining guide and find the right compound that will work with the gap you have.
 

Flow-Rider

Burner
It will never work long term no matter what loctite you use, it isn't designed to replace steel. I've installed automotive gears boxes on a commercial level for over 35 years. Shortcuts always have their consequences on cars.
 
Top