Front Main Seal replacement questions (M30B30)

[vanbavaria]

So started the ‘72 Bavara this morning to do a service and noticed a nice transverse oil spray line forming on the garage floor. I can see the oil flinging out from behind the vibration dampener upon closer inspection.

My Question?

1) has anyone replaced there front main oil seal and have any pointers?
2) do you have to remove the lower timing chain cover to replace or can you manage to do the replacement on engine?

Any info or sources would help, summer is around the corner and I want to have everything tickaty boo for cruising.

Thanks everyone!

 

[billpatterson]

Hi there
Its pretty straight forward. Mainly creating access by removing pulleys and harmonic balancer. I would remove the radiator too to increase working room and to not damage it. Behind the balancer is a large nut and the flange the balancer is bolted too. The nut is super tight ~300 ft-lbs so you need to brace the flange and use a heavy duty breaker bar. I made a brace out of 1/4" x 1.5" flat iron bar (~3' long) that bolts to the flange and braces against the floor. Once the nut is off, the flange can be pried off the end of the crankshaft. The seal is then accessible, can be pried out and replaced.

All the best,
Bill

 

[vanbavaria]

Hi there
Its pretty straight forward. Mainly creating access by removing pulleys and harmonic balancer. I would remove the radiator too to increase working room and to not damage it. Behind the balancer is a large nut and the flange the balancer is bolted too. The nut is super tight ~300 ft-lbs so you need to brace the flange and use a heavy duty breaker bar. I made a brace out of 1/4" x 1.5" flat iron bar (~3' long) that bolts to the flange and braces against the floor. Once the nut is off, the flange can be pried off the end of the crankshaft. The seal is then accessible, can be pried out and replaced.

All the best,
Bill

View attachment 139820

This is good stuff. The pic really helps thank you. You know the size socket that fits on that crank shaft nut?

 

[billpatterson]

This is good stuff. The pic really helps thank you. You know the size socket that fits on that crank shaft nut?

I think its 36mm x 1/2" drive.

I added a pic of the brace.

Cheers

 

[vanbavaria]

My god the pics of your breaker bar and brace just came in . Ok well that gives me a really good idea of how to prepare.

 

[billpatterson]

My god the pics of your breaker bar and brace just came in . Ok well that gives me a really good idea of how to prepare.

The nut is TIGHT. Doing it on the ground is interesting to think about. I know it is done though. I am sure others will chime in. I would want to know how others have 'braced' to loosen/retighten the NUT. I wonder if leaving the car in gear is the method?

Oh ya...you do not need to remove the lower timing cover. The seal is pried out of and gently tapped into the cover.

Cheers

 

[vanbavaria]

The nut is TIGHT. Doing it on the ground is interesting to think about. I know it is done though. I am sure others will chime in. I would want to know how others have 'braced' to loosen/retighten the NUT. I wonder if leaving the car in gear is the method?

Cheers

I love how the Haynes Manuel just says to remove the transmission bell bottom cover and have a person jam a flat head screw driver on the starter ring gear to stop engine rotation………

 

[vanbavaria]

The nut is TIGHT. Doing it on the ground is interesting to think about. I know it is done though. I am sure others will chime in. I would want to know how others have 'braced' to loosen/retighten the NUT. I wonder if leaving the car in gear is the method?

Oh ya...you do not need to remove the lower timing cover. The seal is pried out of and gently tapped into the cover.

Cheers

I’m guessing 1/2 impact won’t cut it either.

 

[billpatterson]

I’m guessing 1/2 impact won’t cut it either.

Likely not enough room or torque.

 

[sfdon]

words of past woes….

use a 3/4 “ breaker bar.

use a floor jack handle as an extension

when you hear the “crack! “ you will know you have beaten it.

 

[Stevehose]

Heat the nut with a torch.

 

[vanbavaria]

words of past woes….

use a 3/4 “ breaker bar.

use a floor jack handle as an extension

when you hear the “crack! “ you will know you have beaten it.

Cheers I’ve dealt with crank shaft bolts in the past on other vehicles and know that it can be a major pain. but that size of a nut (36mm) as bill said on the end of the M30 engine is impressive.

 

[vanbavaria]

Heat the nut with a torch.

Heat can always be the last resort sure. I’ve been meaning to invest in a portable oxy/Acetylene torch kit. Hopefully it won’t come to that.

 

[vanbavaria]

Heat the nut with a torch.

I wonder if a MAP torch would get it hot enough if it came down to it.

 

[billpatterson]

I wonder if a MAP torch would get it hot enough if it came down to it.

No need for heat just leverage; a 36" breaker bar means about 100 lbs of force to loosen.

 

[vanbavaria]

Can anyone confirm it’s a 36mm crankshaft nut? Figure I’ll order the socket.

 

[billpatterson]

Can anyone confirm it’s a 36mm crankshaft nut? Figure I’ll order the socket.

Hi there
Yes...confirmed...36 mm x 3/4" drive. Got a inexpensive one from Princess Auto.

You may be able to loosen it from above (vs on the floor) with the rad out and hood off.

Also, there are a few flywheel locks out there too that may be helpful
https://www.google.com/search?q=fly...sDgkQ_AUoAnoECAIQBA&biw=1522&bih=706&dpr=1.25

Cheers

 

[vanbavaria]

Hi there
Yes...confirmed...36 mm x 3/4" drive. Got a inexpensive one from Princess Auto.

You may be able to loosen it from above (vs on the floor) with the rad out and hood off.

Also, there are a few flywheel locks out there too that may be helpful
https://www.google.com/search?q=fly...sDgkQ_AUoAnoECAIQBA&biw=1522&bih=706&dpr=1.25

Cheers

Hey that might make life a little easier thanks for the info!

 

[m5bb]

Speaking from a lot of experience, flywheels locks are the way to go if you can get one on there.
Soak the nut for a day or two with PB blaster or equivalent.
A map gas torch is sufficient to heat it up. Heat and cool a few times as the expansion and contraction will loosen the nut.
If it's never been off it can be a bitch.
I have done it from above with a 4-5 ft bar on the socket.
It takes all my weight to get it to pop.
If you can get a big impact tool in there that would be an excellent alternative. And may not need a flywheel lock.
Radiator out but AC condenser may have to be taken loose (not disconnected if you have AC) as well to get room.
Next is getting the flange off.
Sometimes they come off easily and sometimes getting the flange off is the hardest part of this job.
A really good puller and again some heat will really help.
I have had to cut the side of the flange with a Dremel tool to get one off before. Hope this doesn't happen to you.
Good luck, take your time and let us know how it goes.
Gary

 

[vanbavaria]

Speaking from a lot of experience, flywheels locks are the way to go if you can get one on there.
Soak the nut for a day or two with PB blaster or equivalent.
A map gas torch is sufficient to heat it up. Heat and cool a few times as the expansion and contraction will loosen the nut.
If it's never been off it can be a bitch.
I have done it from above with a 4-5 ft bar on the socket.
It takes all my weight to get it to pop.
If you can get a big impact tool in there that would be an excellent alternative. And may not need a flywheel lock.
Radiator out but AC condenser may have to be taken loose (not disconnected if you have AC) as well to get room.
Next is getting the flange off.
Sometimes they come off easily and sometimes getting the flange off is the hardest part of this job.
A really good puller and again some heat will really help.
I have had to cut the side of the flange with a Dremel tool to get one off before. Hope this doesn't happen to you.
Good luck, take your time and let us know how it goes.
Gary

Cheers for the info Gary luckily I have access to plenty of puller options at work. You have any recommendations for a flywheel lock that works for the M30 that works with the transmission still in place?