Rear main seal '32-'38?

[36tudordeluxe]

Did the '32-'38 flatheads have rear main seals as I don't see them offered in my catalogs? Am looking at my rear main bearing cap on my '36 engine and I do see a seal on the outside of the cap that would mate to the oil pan but I can't find that seal for sale either. What do I need?

[alanwoodieman]

they did not have a rear seal -just a set of slinger rings with the last one allowing the oil to drain back into the pan thru a small pipe screwed into the lower rear bearing cap

[36tudordeluxe]

Thanks Alan, are the rear slingers integral to the crank as I don't remember installing them like I did on the front slinger?

[ckh]

I'm no expert, but maybe this will help. On my 35/early 36 engine with babbit main bearings, the upper part of the seal, which I believe is made of some type of alloy, is pressed into the block by hand prior to installing the crank. The lower part of the seal is cast into the rear main bearing cap. There is no rope seal used on the rear main on this engine. As far as what goes between the bearing cap and the pan, I don't know.
I haven't got that far yet. Maybe nothing?

[36tudordeluxe]

Originally Posted by ckh

I'm no expert, but maybe this will help. On my 35/early 36 engine with babbit main bearings, the upper part of the seal, which I believe is made of some type of alloy, is pressed into the block by hand prior to installing the crank. The lower part of the seal is cast into the rear main bearing cap. There is no rope seal used on the rear main on this engine. As far as what goes between the bearing cap and the pan, I don't know.
I haven't got that far yet. Maybe nothing?

I see now when you buy the pan gaskets for the '32-'38 it comes with a cork strip for the pan to cap surface.

[Bluebell]

Sponsored Links (Register now to hide all advertisements)

The slinger on the crankshaft is a ring that is part of the crank (yes. Integral), It is quite a bit bigger in dia. than the rest of the rear main journal.
Later, you could install a seal by having the crank grinder grind that flange off. You also needed to buy and install the upper and lower seal carriers (narrow gap) The alloy seal carrier is only a little different than the slinger housings. I have seen people try to install a seal in the slinger housing, which you cannot do.
The cork strip is to seal the pan at the outside of the rear main bearing cap.

The rear main seal arrangement was introduced with the advent of the Hydrovent system (Positive crankcase ventilation) because the PCV system(without the seal) would have pulled dirt in around the rear main. This would have caused accelerated wear to the engine.

[Brian]

'Later, you could install a seal by having the crank grinder grind that flange off. You also needed to buy and install the upper and lower seal carriers (narrow gap) The alloy seal carrier is only a little different than the slinger housings. I have seen people try to install a seal in the slinger housing, which you cannot do.'

This pertains only to 37-38 engines which had the upper and lower die cast inserts. The earlier engines had the arrangement as described by CKH.

'The rear main seal arrangement was introduced with the advent of the Hydrovent system (Positive crankcase ventilation) because the PCV system(without the seal) would have pulled dirt in around the rear main.'

Not quite true....crankcase ventilation was introduced in 1935, the positive rear seal arrangement began in production around 38-39. Indeed, those 91/99 era engines can be found with both slinger and seal type crankshafts.

[flatheadfan]

This may have occurred earlier but, as far as I know, starting with the '36LB Ford used a couple of replacement inserts which fit into the block. On the rear of the crankshaft there is a blade that fits into the insert groves. Once the crank is turning it slings the oil exiting from the rear main out and into the pan. It works but is not as efficient as the replacing rope insert.

Tom

[cretin]

I'm a little confused. On my '37 engine I'm currently assembling, I have the inserts shown above. Nothing goes on there? I have a fel-pro gasket set for the engine, and it says it includes 2 front crank seals, and 2 rear main seals. I have 2 shorter, wide rope seals, and 2 longer, thinner rope seals. Do the longer thinner ones go in the groove of these inserts?

[cretin]

I suppose my gasket set supports a range of years and some may have used the rope seals?

[flatheadfan]

Nothing goes in the "grooves."

Tom

[cretin]

I asked in another thread too. Thanks for the info.