Main Bearing Cap Removal

[robcadle]

Hello, I’m tearing down my Healey engine and I’m ALMOST done. Got stuck on the main bearing caps. The third one (from front) came off just fine but the rest are stuck. Any suggestions? Workshop manual calls out a special service tool and I see threaded holes in the caps that look like they’d be useful for this. Any suggestions.

Also, the front and rear bearing caps seems to form an oil seal at either end of the crank. Not clear how I break these out. Any advice?

Thanks,
Rob

 

[Randy Forbes]

They must be pulled straight up__NO HAMMERS!

I made this up sometime during the 70s; works on B & C series engines.

Austin-Healey West sticker remnants; I bought my car there in 1978, then went to work for them later that year.

Bushing is only used for rear main cap.

 

[robcadle]

Thanks, Randy! This forum is really proving to be a lifesaver. Two follow-up questions:

1) any chance the C-series main bearing studs are also 1/2-20 (like MGB studs)? I have two available.

2) for the modified bush for the rear bearing cap, did you just retap the 1/4 NPT ID of the adaptor to 1/2-20?

Thanks!
Rob

 

[Randy Forbes]

Thanks, Randy! This forum is really proving to be a lifesaver. Two follow-up questions:

1) any chance the C-series main bearing studs are also 1/2-20 (like MGB studs)? I have two available.

2) for the modified bush for the rear bearing cap, did you just retap the 1/4 NPT ID of the adaptor to 1/2-20?

Thanks!
Rob

I'm thinking the Healey's main studs are larger__I've slept since I built the last one, so can't say for sure.

And yes, just drilled and tapped a reducing bushing to suit.

 

[bob hughes]

Mmm when I removed my caps I made a similar bracket to the one randy has but I did use a slide hammer to raise the caps. I don't think that I created any damage by doing that. - - I hope!



Bob

 

[Randy Forbes]

Mmm when I removed my caps I made a similar bracket to the one randy has but I did use a slide hammer to raise the caps. I don't think that I created any damage by doing that. - - I hope!



Bob

Nope, you're good! Nowadays__with a broad range of slide-hammers at my disposal__I might've done the same thing

I just wanted to discourage anybody from trying to tap them upwards using a hammer, too many surfaces that can get damaged.

 

[roscoe]

One of my favorite tools, not that I would have used it for this particular job, is a slide hammer attached to a vise grip pliers. Just weld the proper threaded nut to the adjuster on your vise grips and thread it onto the shaft. Wonderful for pulling lip seals out of housings by drilling a small hole in the seal, starting a PK screw in it and clamping the vise grips on. I don't think you can wear out a slide hammer but mine has seen a lot of use over the last 35 years.

 

[robcadle]

Thanks everyone for the help. I thought I'd close this thread out with a conclusion.

I followed Randy's approach and made a less elegant tool that was matched to my fabrication skills. I confirmed that the main studs in the C-series engine are 1/2-20 and they will thread into the caps (well the first three anyway).

Parts list:
main stud removed from bearing #3 (it was easy to remove this cap by hand)
1/2" x 1/4" NPT coupler, with the 1/4" NPT retapped to 1/2-20 (coupler only used for rear bearing)
1/2-20 nut
Short piece of angle iron
Two 2x4's

The fully threaded stud Randy put in his picture would have been better. The threading on the C-series stud is not full and I could only pull the cap half way off before I bottomed out the threads. I just backed off the nut and put a some different thickness pieces of wood under the angle iron.

Was able to get everything out easily. A couple pics attached.

 

[Randy Forbes]

Thanks everyone for the help...

... Was able to get everything out without dinging up the caps.

Good job!

Now that you mention it, I believe I DID have to run the (1/2x20) die all the way down the stud, to get them lifted without refixturing. Once you get it 2/3rds-3/4ths the way out, you can usually pull it the rest of the way by hand.

Glad it all worked out for you :

 

[Rreford]

Good job!

Now that you mention it, I believe I DID have to run the (1/2x20) die all the way down the stud, to get them lifted without refixturing. Once you get it 2/3rds-3/4ths the way out, you can usually pull it the rest of the way by hand.

Glad it all worked out for you :

I am at the point of removing the crankshaft main caps, and I appreciate this thread. I just wish the photos would still populate so I think I can get a 1/2-20 bolt and rig it up with a slide hammer to remove cap #1, #2, #3. I am unclear about how best to remove the rear main cap. Is the threading in the rear main cap (clearly much larger) NPT threaded?

 

[robcadle]

funny I just reread my old post and didn’t really remember any of what I wrote. Glad I documented it!
I was able to remove all of the main bearing caps by hand except the rear one. Yes, that one is threaded with a 1/2 NPT thread.

I bought a brass coupler from the hardware store that converts 1/2” NPT to 1/4” NPT. Then I retapped the 1/4” NPT part of the coupler with a 1/2-20 tap so that an extra main stud would thread into it. The soft brass is easy to retap to the 1/2-20 thread.

I then drilled a 1/2” (plus a little) hole in a piece of angle iron, place it near the top of the stud spaced out from the block with some 2x4’s, and threaded on a main stud nut to gently lift the rear main bearing cap out. It worked beautifully.

 

[Randy Forbes]

Main bearing cap puller

Remnant of the Austin-Healey West shop I worked at back in San Francisco, circa 1970s when I made the fixture__and used it a lot too!

Adapter for pulling out the #4/rearmost Healey cap. The tool also works on MGB engines (maybe Spridgets too, can't remember...).

 

[Bob_Spidell]

I swear Randy should go into the tool business