I am hoping someone could help with my unique problem.

My Son and I have rebuilt my late Fathers Ford 640 Tractor.   It is a 134 cu inch, 4 cylinder, 8 valve, gasoline engine manufactured in 1955.  We have completely rebuilt the tractor from front to back.  We replaced the rear main rope seal with a 2 piece neoprene Fel-Pro seal and had an instant leak.   The tractor forums suggest the Victor Reinz brand of seal but it was identical to the Fel-Pro brand and leaked just as bad.  After multiple tries and speaking with every tractor mechanic we could find we were no closer to finding a solution.  All of the older tractor mechanics in our area that once worked on these are no longer with us.

While surfing the internet I stumbled upon  Y Blocks Forever and the rare occasion of the seal grove in the block being deeper than the seal.  To verify this leak we have pressurized the engine block with compressed air and checked for leaks with a soap solution.  BINGO The rear main is leaking from the seal in the block.  I measured the seal grove and found this to be the case with this tractor and the cause of the leak.   The block groove is 2mm deeper than the cap groove allowing a leak between the block and seal. 

I spoke with Ted Eaton and Don Hyde on the phone and both recommended the 2 piece neoprene seal over the rope seals.  I have also found others that recall a shim kit that was available for this problem once upon a time but it is no longer available. 

Can anyone comment on the shims?  I am thinking I could manufacture a shim (metal, synthetic gasket material, or otherwise) to take up the additional space in the block and then seal the shim and rear main seal to the block and cap with Permatex Ultra Black Maximum Oil Resistant RTV Silicone Gasket Maker or Victor Reinz Aluminized Silicone Gasket Maker.  The Victor Reinz Aluminized Silicone Gasket Maker is manufactured to seal the rear main cap to the block instead of using crankshaft oil seal packing. 

Has anyone tried the shim method or have any other suggestions? 

Thanks in advance
Patrick Burchett

the shim kit was used on the rope seals.going back to the rope seal may solve your problem trouble is the rope seals today are no good.you may be able to find an old one.im sure others will come on here with lots of ideas.

Can you post the depth and width of the main seal groove?  The measurement of the main journal holes in the block would also be helpful as I don’t think I have any literature here showing those tractor dimensions.  I can compare those dimensions to the ones for the Ford Y.

Lorena, Texas (South of Waco)

When I pulled my motor apart last Winter to reseal and new Gaskets I also replaced the Rear Main Seal. The One that was in it was a C1TT # which is for a Ford Tractor. Didn't Seal too well as the Lip Stuck out too far and was flattened against the Crankshaft. No Idea why they didn't just get the correct Y Block Neoprene Seal instead of the Tractor Neoprene Seal.

  

Here is a few measurements that I took.  The photos show these measurements. 
Seal Shaft Journal = 2.622 in  /   66.60 mm
 
Block Groove Depth = 0.285in   /   7.25 mm
 
Cap Groove Depth = 0.218 in   /  5.55 mm
 
Seal Groove Bore = 3.19 in /  81mm
 
Seal Groove Width in Bore = .185 in  / 4.7mm
Seal Groove Width at Opening = 0.236 in  / 6 mm
 
 
Here is the seals that I researched to fit.  The Victor JV 745 has an unknown ID as the tech rep at Victor said they did not have that data on 2 piece seals.    I do not think the Chrysler 318 seals will work.   

Victor Reinz
 JV 745        OD=3.237       ID=(?)         Width = 0.308   This is specified for this tractor and also fits the
                                 1954-1972 Ford 272 & 292 engines. 
 
JV 606        OD=3.30         ID= 2.64     Width = 0.340      This fits a 1975-1984 Chrysler 318 cu in
 
 
 
Fel-pro
 BS 3141 or (BS 6141-3)    OD = 3.22      ID =2.595   Width = 0.220     This is specified for this tractor and
                                                                                                                         also fits the 1954-1972
                                                                                                                          Ford 272 & 292 engines. 
 
 BS 40245    OD = 3.307   ID= 2.64  Width = 0.320   This fits a 1975-1984 Chrysler 318 cu in

I measured a ECG (272/292) rear seal retainer and here are the dimensions of the rear seal groove.

O.D. – 3.200”

I.D. – 2.720”

Width at O.D. of grove – 0.200”

Width at I.D. of groove – 0.240”

 

Here are the dimensions of the rear seal groove in the block.

O.D. – 3.200”

I.D. – 2.700”

Width at O.D. of groove – 0.190”

Width at I.D. of groove – 0.240”

Lorena, Texas (South of Waco)

...replaced the Rear Main Seal. The One that was in it was a C1TT # which is for a Ford Tractor.

CITT is a Heavy Truck PN Prefix. Usually, a tractor dedicated PN Prefix last character was N to differentiate the part ID to tractor dedicated.

The CASTING ID NO on the retainer is EAF which will most likely need a TRACTOR Parts Catalog to find the correct seal or arrive at a later replacement.

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