Front crank/timing cover seal leak.... MAXIMUM ANNOYING

[CamTheHedgehog]

So....... I just finished the timing job on my 4.0L SOHC. About 500 miles ago. I got under my truck today. to see if there were leaks. The rear main, upper, and lower oil pans do not appear to be leaking (maybe a bit of seepage from the rear main but I'm ok with that). So that's good. However the front crank seal appears to be leaking a decent amount. I did replace it during the timing job, with the included seal in the Fel-Pro front cover kit. My first indication should have been that I could push the seal into the bore in the cover with my fingers...... yea hindsight is 20/20. I did align it with the crank, not with the special tool but with the oil slinger and calipers, scooting it back and forth until centered so I doubt that's the reason. I also installed the seal to the same depth as the original, and maybe I shouldn't have done that.

Anyway, vent over. What I want to ask is a) what brand seal should I go with for round two of this replacement? And b) any tips or tricks to know for doing this? Silicone on the outside, (hopefully not) removing the timing cover and re-centering, etc. I really don't want to have to deal with the stupid crank pulley bolt any more than I have to.

 

[franklin2]

There are a lot of bad parts out there. Do a google search and see if anyone else has had a problem like yours.

On a different vehicle I was rebuilding the engine. The wise engineers decided to make the timing cover out of plastic, and incorporate the seal into the cover. So I bought the replacement setup from Dorman. It leaked. Tore the front of engine down, put another Dorman cover on it, leaked again. Did some google searching, I was not the only one having this problem, and someone mentioned they went with the A/C Delco part and no more leak for them. I tried it and sure enough, no more leak with the other brand cover.

So what are your choices from Ford on this seal? Is the timing cover plastic or metal?

 

[CamTheHedgehog]

Hey @franklin2, sorry for the delayed response. I was dealing with the stupid little devil that is the dreaded rear spring hanger (PO only did one and left the other one for me.... yay).
It is an aluminum cover, with a simple bore for the seal. No shoulder, you just press it in to the "correct depth"- there is a special ford tool for that, but I just measured with calipers before removing the old one and reinstalled the new one to the same depth. I think part of the problem may be me not using the tool, I am not sure.

As far as new seals go, I have the following options:
BCA-(NTN's seal division)- $6.94
National- $7.03
Timken- $11.43
And finally the OEM ford seal, 5H2Z-6700-AA, for $22 at the local dealer.

 

[Shran]

I haven't done a front seal on a SOHC cam engine but plenty on OHVs... the process sounds similar, just a simple bore with no shoulder. I am not sure that seal depth matters though as long as it is past the edge of the bore - the balancer has about 1/2" of sealing surface for the seal lip to ride on. So on OHV engines there can be several failure points -

- the seal lip can partially roll over on itself as the balancer is inserted
- if there is a groove from an old seal on the balancer, it may never seal in that one spot
- if the timing cover is not aligned with the balancer, the seal will not be centered on the balancer
- if the seal is grossly crooked, it may cause a leak

Any one of those is pretty easy to do... especially the first one. Just had that happen a couple days ago, it is very hard to see even with the engine out of the truck. I have another front seal that is leaking and I'm guessing it's because of that.

A very annoying place to find a leak, to say the least. I would almost rather pull a transmission and replace a rear main that do a front main with the engine in the truck.

 

[CamTheHedgehog]

I haven't done a front seal on a SOHC cam engine but plenty on OHVs... the process sounds similar, just a simple bore with no shoulder. I am not sure that seal depth matters though as long as it is past the edge of the bore - the balancer has about 1/2" of sealing surface for the seal lip to ride on. So on OHV engines there can be several failure points -

- the seal lip can partially roll over on itself as the balancer is inserted
- if there is a groove from an old seal on the balancer, it may never seal in that one spot
- if the timing cover is not aligned with the balancer, the seal will not be centered on the balancer
- if the seal is grossly crooked, it may cause a leak

Any one of those is pretty easy to do... especially the first one. Just had that happen a couple days ago, it is very hard to see even with the engine out of the truck. I have another front seal that is leaking and I'm guessing it's because of that.

A very annoying place to find a leak, to say the least. I would almost rather pull a transmission and replace a rear main that do a front main with the engine in the truck.

Good to know.
The SOHC is pretty easy, the hardest part is the devil bolt that has NO NEED to be as tight as it is

 

[gw33gp]

One trick I learned over many years of building race engines is to smear a little grease on the seal to lubricate the sealing surface at start up before oil gets on it to lubricate it. A dry seal can result in a lot of wear before oil gets to it.

I used all OEM parts when I rebuilt the cam timing chain system about 50K miles ago. Still no leaks but a little dampness near the rear main seal. I never see a drop on the ground though.

 

[Shran]

Good to know.
The SOHC is pretty easy, the hardest part is the devil bolt that has NO NEED to be as tight as it is

The crank bolt? My M18 mid torque 3/8 impact removes those easily… not that tight… unless you only have hand tools, then it sucks.

I use Vaseline to lube up seal lips.

 

[CamTheHedgehog]

The crank bolt? My M18 mid torque 3/8 impact removes those easily… not that tight… unless you only have hand tools, then it sucks.

I use Vaseline to lube up seal lips.

It’s not loosening, it’s tightening that’s the issue

My impact will remove it just fine lol.

 

[gw33gp]

I use Vaseline to lube up seal lips.

I use Vaseline on seals that contact water but prefer grease on seals that contact oil. No specific reasoning, it is just what I do.

 

[Shran]

It’s not loosening, it’s tightening that’s the issue

My impact will remove it just fine lol.

This is what I use to hold the balancer:

You can wedge it against something or just hold it, torque spec on those is 30-37ft/lbs IIRC with another 90 degrees past that to get to TTY. If you have a long 1/2" drive torque wrench for some leverage it's pretty easy.

 

[CamTheHedgehog]

This is what I use to hold the balancer:
View attachment 107427

You can wedge it against something or just hold it, torque spec on those is 30-37ft/lbs IIRC with another 90 degrees past that to get to TTY. If you have a long 1/2" drive torque wrench for some leverage it's pretty easy.

Good to know. I have a wimpy rubber strap wrench, but I have a feeling it’s not gonna work good enough.

 

[CamTheHedgehog]

Looking for a chain wrench now- is that a 12” or a 24”?

 

[Shran]

Edit - 12" one is what I have

Yeah those chain strap wrenches don't look useful but once you have one, you will find all sorts of uses for it. No pipe wrench big enough? chain wrench... need to torque stuff like this? chain wrench.. need to turn something awkward? chain wrench... you get the idea. One of the best $20 I have spent on tools.

 

[CamTheHedgehog]

I’ve thought about getting one for a while, I’d have all sorts of uses for it. Having an actual repair that needs it is, as usual, what pushes me over the edge.

Once again, thank you all for your help!

Now to deal with my local ford dealer’s parts department, because I don’t wanna wait for shipping. Yay.

 

[franklin2]

I haven't done a front seal on a SOHC cam engine but plenty on OHVs... the process sounds similar, just a simple bore with no shoulder. I am not sure that seal depth matters though as long as it is past the edge of the bore - the balancer has about 1/2" of sealing surface for the seal lip to ride on. So on OHV engines there can be several failure points -

- the seal lip can partially roll over on itself as the balancer is inserted
- if there is a groove from an old seal on the balancer, it may never seal in that one spot
- if the timing cover is not aligned with the balancer, the seal will not be centered on the balancer
- if the seal is grossly crooked, it may cause a leak

Any one of those is pretty easy to do... especially the first one. Just had that happen a couple days ago, it is very hard to see even with the engine out of the truck. I have another front seal that is leaking and I'm guessing it's because of that.

A very annoying place to find a leak, to say the least. I would almost rather pull a transmission and replace a rear main that do a front main with the engine in the truck.

I forgot to mention to look for the groove in the balancer. You will have to take it back off to see it. Most high mileage engines do wear a groove in the balancer. They make repair sleeves to fix it.