Home 
> Jensen Healey & Jensen GT Tech > Engine & Transmission > Late Engine Rear Crankshaft Seal

 Moderated by: Greg Fletcher  
AuthorPost
bora450
Member
 

Joined: 06-25-2013
Location: Thousand Oaks, California USA
Posts: 17
Status: 
Offline
To date, I have rebuilt Triumph TR6, Porsche 944 Turbo and Maserati V8 engines. All of these have shaft seals where the outside surface is pressed flush with the surrounding surface.

I am now checking and cleaning 1974 J-H engine parts in preparation for reassembly. The old rear crankshaft seal surface protrudes from the cover plate by .05. I have a second engine with the seal installed identically. The Workshop manual does not address seal installation.

I have reviewed all of the posts about rear seals and didn't find any comments about this so I solicit them now.

Thanks, Claus

Brett Gibson JH5 20497
Member
 

Joined: 03-17-2005
Location: Hilton, New York USA
Posts: 798
Status: 
Offline
Hello Claus, it's very important that you do not seat that rear main seal flush, go with the measurement you got and you should be trouble free, it has to do with just were the seal lip rides on the crank surface and the amount of end float the crank has, in to close and the seal gets eaten. At least you have a later engine and not one of the wrope seal early ones, they are not very forgiving and tend to leak abit more often.

Brett

bora450
Member
 

Joined: 06-25-2013
Location: Thousand Oaks, California USA
Posts: 17
Status: 
Offline
Thanks Brett,

I did notice that the polished area on the crankshaft was close to the block side of the flange so that makes sense.

In anticipation that there was a good reason for the seal offset, I machined a .100 thick aluminum spacer yesterday to fit inside the bore. When I press the seal against the spacer it will be in the same place.

Claus

Dakota123
Member
 

Joined: 03-20-2009
Location: Colorado USA
Posts: 185
Status: 
Offline
For piece of mind, you can grease the seal, push the cover/seal into position, then remove. The grease will leave a smear on the flange and you can tell exactly where the seal will ride.

George
Member
 

Joined: 04-05-2005
Location: Boyds, Maryland USA
Posts: 88
Status: 
Offline
Thought I would resurrect this topic for a quick question.

I see the rear seal is offset from the edge of the cover plate, but I am still not entirely clear which way. Is it .100 of an inch further in toward the engine, or .100 proud sticking out the back of the plate toward the rear of the car?

Thanks
george

bora450
Member
 

Joined: 06-25-2013
Location: Thousand Oaks, California USA
Posts: 17
Status: 
Offline
The seal should be sticking out .100, away from the engine. I machined an aluminum disk to fit into the recess on the engine side and pressed the seal in until it bottomed on the disk. That way the seal would be straight.

Esprit2
Member
 

Joined: 05-01-2005
Location: Minneapolis, Minnesota USA
Posts: 573
Status: 
Offline
The important dimension is that the seal must be recessed 2.5mm (0.100 inch) from the inside machined face of the seal housing. How far the seal ends up sticking out of the housing just is what it is. See the attached JPEG.

Attachment: 9XX Main Seal Housing - Rear - Installation into Housing, 2.5mm, 84kb.jpg (Downloaded 99 times)

Last edited on 06-19-2014 03:19 pm by Esprit2

George
Member
 

Joined: 04-05-2005
Location: Boyds, Maryland USA
Posts: 88
Status: 
Offline
Thanks everybody !



UltraBB 1.172 Copyright © 2007-2011 Data 1 Systems