Tracking Down a Leak (1 Viewer)

[skidrocket]

Hey guys,

I wondered if you might be able to help me track down the source of a drip on a '76 FJ40? It's not leaking too awfully bad, a 2-3 inch puddle after sitting for a month while I replace the cluctch slave cylinder, hose, and steel line. I wondered if it may be originating from the transmission then running down the inside of that housing? Any help or advice would be greatly appreciated.

 

[D'Animal]

Looks like the inspection cover for your clutch flywheel area.

I will throw a guess out and say it is you rear main seal. I base this on the looks of your oil pan.

It could be your front transmission input shaft seal. If the seal between the T-case and the trasmission leaks, your fluid from you t-case will work its way into the transmission and overfill it. Check the fluid levels in both. If you Transmisison is over full and your T-case is low, that seal is bad. How does that get to you inspection cover you ask? If the breather is bad on your transmission the heating of the oil will cause an increase of pressure in the case and may force the oil out the seal, if you shifter is tight.

Just my thoughts.

 

[cpratt]

I have the same issue. When I took the cover off and looked, thinking it was a rear main, the engine side and clutch was completely dry. There appeared to be a plate on the transmission side with 8 or 9 small bolts that were rather loose. Tightening those mostly took the problem away, I'm wondering if that gasket could be bad. Worth a look though.

 

[Adventure Teq]

Start with a pressure wash at the car wash. Then use some brake cleaner or other oil remover (not degreaser) and spray it all over the suspect areas to dry everything up. Then watch for the leak. First without running it probably, then if nothing run it. Just an idea.

 

[Pin_Head]

Start with a pressure wash at the car wash. Then use some brake cleaner or other oil remover (not degreaser) and spray it all over the suspect areas to dry everything up. Then watch for the leak. First without running it probably, then if nothing run it. Just an idea.

X2

This is the only way to tell where it is leaking from as opposed to where it is dripping from.

A trick is to dust the clean metal with talcum powder or corn starch to help visualize the oil tracks.

 

[psuknow98]

I have the same problem! Get a blue LED light and shine it under there. It makes oil GLOW.... Good way to find out where its leaking

 

[KgB]

curious

Start with a pressure wash at the car wash. Then use some brake cleaner or other oil remover (not degreaser) and spray it all over the suspect areas to dry everything up. Then watch for the leak. First without running it probably, then if nothing run it. Just an idea.

why not degreaser and what is the difference between oil remover and degreaser?

I agree with advice,got to get area cleaned up first.

 

[Adventure Teq]

why not degreaser and what is the difference between oil remover and degreaser?

I agree with advice,got to get area cleaned up first.

Well from my experience cleaners like engine degreasers and the like merely break up the grease when allowed to soak, thus allowing for a good scrub down and rinse with a hose. But brake cleaner, carb cleaner, and or starter fluid essentially remove any residual light films that may be left afterwards. It's just the best way to get rid of all the oils and get down to the bare metal. And the cans generally give you enough pressure to blast away alot of gunk.

Could use both but the latter as a final wash.

 

[bsevans]

I would also wipe the leak onto a rag and smell it. Gear oil and engine oil have to different smells. I have seen this leak come from both directions (engine rear main or oil seals (plugs) in the rear block) or the front seal on the tranny. If it smells like gear oil the you might want to check the gear oil level in your transfer case. If the level is low then your seal between the tranny and transfer case is leaking allowing the gear oil in the tranfer case to be pumped into the tranny which can cause the front seal to leak from over pressure.

 

[D'Animal]

Your pan gasket could need the bolts retorqued as well.

 

[skidrocket]

Thanks for all the advice guys. Now that I've completed the work on the clutch, I'm going to start by cleaning this area up as you suggested. Then hopefully I can track down where the fluid's originating from.

 

[Rocky_LC]

There is also the possibility of leaks occurring from two plugs on the back of the engine (Cam & an Oil Gallery Plug).

The bell housing needs to be removed (a major project) to access.

I don't know how a person could tell which of the three locations the problem is, if you determine the oil leak is coming from behind (from the engine side) the flywheel.

Here's a thread on on it. See post #23 for a picture.

https://forum.ih8mud.com/40-55-series-tech/21876-oil-leak-rear-engine.html

Rocky

 

[Rocky_LC]

Here's My Leak..

I am leaking from the oil gallery plug.



Did I get the wrong plug?



Should I change out this freeze plug? (I know the answer... Yes. I don't want to go back in here for a while).




How about the rear main? How hard is it to replace? Should I do it now?

Can I get the oil pan gasket without having the tranny / transfer removed?

Neither of these seem to be leaking.


Thanks for the advice.

Rocky

 

[Adventure Teq]

How about the rear main? How hard is it to replace? Should I do it now?

Can I get the oil pan gasket without having the tranny / transfer removed?

Neither of these seem to be leaking.


Thanks for the advice.

Rocky

The rear main is really easy when you have the flywheel off. Just hook in and pop it out then lube up the new one and gently tap it in.

Yes you can get the oil pan off with those still installed.

 

[Colorado Boy-74-FJ40]

When you de-grease and clean the engine you will get even more leaks. I did that with mine and removed the coagulated grease that was acting as a seal. It really started leaking then. It has goobed up now and I only lose about a quart every 1000 miles now.

 

[Rocky_LC]

Great. It's amazing how much crap is on this thing (bellhousing / tranny / transfer).

I wish I could just leave things alone, but I'm this deep in it now.

Thanks for the advice.

Rocky

 

[skidrocket]

Just as an update. I checked my fluid levels today and the transmission was over full while the transfer case was indeed low. So, it looks as if you guys suspected correctly. It's probably the seal between the transmission and the transfer case, causing the excess fuild to leak out the front seal. Now to find the kit that takes care of this.

 

[Bodean]

They make a hose that screws into both fill plug holes if you want a temp. fix for the tranny/t-fer issue. I think I bought one a long time ago from Man-a-Fre. Your local auto parts guys may be able to make that hose as well.

Later,

 

[bsevans]

Just as an update. I checked my fluid levels today and the transmission was over full while the transfer case was indeed low. So, it looks as if you guys suspected correctly. It's probably the seal between the transmission and the transfer case, causing the excess fuild to leak out the front seal. Now to find the kit that takes care of this.

If you have a business that deals with commercial trucks, like Fleet Sales, You can put together a bypass hose that is far superior to anything you can buy from SOR or Man a Fre and it cost no more. See this link.

Tranny to Transfer Case Bypass Hosel