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Teflon Rear Main Seal -- Installation Difficulty

  • Thread starter Thread starter Eulers
  • Start date Start date Oct 27, 2010

Eulers

Member
Oct 12, 2010
57
3
9
Oct 27, 2010
#1
  • Oct 27, 2010
  • #1
Hi. Am still having difficulty installing a FelPro Teflon Rear Main Seal (#BS40644) into a stock 1987 5.0 (T5 tranny) despite having tried a number of the tips from the various StangNet threads.

Any further suggestions appreciated.

Below I describe my (1.) Difficulty and the (2.) Installation Tips Tried so far.

(1). DIFFICULTY:
(A). The FelPro directions specify to install the seal DRY (in capital bold letters on the instruction sheet). Unfortunately, "DRY" creates resistance so that the seal tends to spring back out from its groove when I'm attempting to tap it in.​
(B). The new Teflon Rear Main Seal seems to hang up on the outer circumference of the seal where it contacts the block.​
(C). Consequently, I cannot get the Rear Main Seal to slide EVENLY into its groove between the block & crank. There is always some portion of the Seal's perimeter (about 15 degrees worth) that pops back out. It's just like playing the Whack-A-Mole Gopher Bash Game. Typically, I get over half the depth of the Seal seated into its groove except for a 15 degree section that keeps springing back out at me.​
(C). My last effort: I finally forced that 15 degree section in with a 3/4" X 2" wood block & rubber mallet. However, upon doing so I heard the sound of plastic snapping or cracking. I imagine it was breakage of the Seal's outer teflon ring as it was forced under the face of the engine block. So, I'm going to remove and try a new Teflon Rear Main Seal again with any of your suggestions.​

(2). Installation Tips I've Tried:
(i). The FelPro Teflon Rear Main Seal comes with its own Seal Installer. I used it in all my attempts.​
(ii). Used the old Main Seal mounted on a thick polycarbonate sheet so I could hammer on the sheet and evenly pressure the new Seal to slide in evenly (theoretically). In reality it did not.​
(iii). Also tried just the old Seal alone on top of the new seal. (I would tap on the old seal with a rubber mallet).​
(iv). Also tried just tapping on the new seal in a star pattern with a 3/4" x 2" wood block and rubber mallet.​
(v). Also tried chilling the new seal b/c it seems to hang up on the outer circumference of the seal when it contacts the block.
​
A bit long-winded but thanks for bearing with me. Any ideas?
 

Rick 91GT

Mustang Master
Nov 29, 1999
9,692
95
99
PA
Oct 28, 2010
#2
  • Oct 28, 2010
  • #2
I usaully have no issues when using the seal installer, I do have a piece of delrin I made that same size as the seal to help push/tap them on. If you can find a piece of tubing or pipe the size of the seal it makes tapping it on much easier...

I always put a very light film of oil on the crank...
 

cardudeusa

Founding Member
Oct 22, 2002
1,744
5
48
Home of the Florida Gators!
Oct 28, 2010
#3
  • Oct 28, 2010
  • #3
I've done it multiple times using the installer they send with it. Never had a problem.
 
8

89drop

New Member
Aug 30, 2009
175
2
0
Oct 28, 2010
#4
  • Oct 28, 2010
  • #4
im thinking in the directions it means the seal should be dry, but maybe lightly lube up the block?
 

Jaswir

Member
Mar 31, 2005
578
0
18
Orlando, FL
Oct 28, 2010
#5
  • Oct 28, 2010
  • #5
never had any problems installing them ive done about 3... just lighty tap it in even all the way around it should just slide right in..
 
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