Oil Overfill - Possible Rear Seal Leak - Steel Soldiers::Military Vehicles Supersite

BugEyeBear · 10-08-2009, 15:21

Yesterday I picked up a recently purchased M35A2 that I've purchased from a private party.

The PO isn't very familiar with Deuces, and accidentally overfilled the crankcase with oil (it is approx 2.5" above the full mark (checked 5mins after running)).
But based on what the PO told me it could be as much as 3 GALS overfull!.

Truck drives great!

BUT has an oil leak around the injector pump and MIGHT also be leaking at the rear main seal (due to overfill, I assume).

I only drove it approx 20miles after pick-up (approx 7miles at city speeds & the rest at 55mph). Drove it straight to a repair shop to have it looked over prior to my 400+ mile drive home.
When I left the seller's house the underside was dry, But after the 20mile drive there is a good coating of oil underneath the engine/trans/xfer.

Appears that most of the oil is leaking from the injector pump (this is already on the list to be fixed). But it might also be spewing oil oit of the hole below the flywheel. (oil spray is visible on the driver's side of the engine & on the driver's side front wheel inner rear fender flap (appears to be from the known injector pump leak) but also under the truck in the center, mostly on the trans & xfercase (guessing this is coming from the rear seal due to crankcase overfill condition)).

I checked oil level again, and it still shows as WAY overfull.

I also crawled under the truck to look at all of the pinion seals & transmission & xfer case seals. Just to be certain that none of these were also leaking. All look fine.

The guys at the repair shop are going to drain off the excess oil (get it back to the proper level), fix the known injector pump leak, clean off the existing oil spray, and start to investigate the source of any additional leaks (might use UV dye to track down the leak source). They will also check all fluid levels.

BTW: They are also replacing a Pass side rear axle seal. This was my initial reason for taking the truck to the repair shop. But this is NOT the source of the oil spray.....

SO MY QUESTION IS:

Has anyone ever overfilled the crankcase, experienced oil leaking out of the rear seal, corrected the overfill, and then had the leak stop once the proper oil level was restored? (i.e. I'm hoping the rear seal is still OK)

Should I expect any impact to the clutch due to possible oil contamination? (seems to shift fine, so I'm hoping it will be OK once the assumed overfill caused leak is corrected.)

What is the function of the 2 threaded holes at the bottom of the bell housing? The one located slightly towards the passenger's side has a plug in it (this one is referred to as being required for deep water fording in the TMs), but the other one (located more towards the driver's side) is open (& appears to always be open in the TMs)

THANKS in advance!

-Bear-

drgreg · 10-08-2009, 18:08

Question 3- One is the fording plug in the stored position (normal operation). The other is the actual bell housing drain, relocate plug to this position when fording.

BugEyeBear · 10-08-2009, 18:23

Quote:

Originally Posted by drgreg

Question 3- One is the fording plug in the stored position (normal operation). The other is the actual bell housing drain, relocate plug to this position when fording.

AH! That makes sense!! Thanks!!

(I was trying to understand why there appeared to be 2 bell housing drains... NOW it makes sense!)

BFR · 10-08-2009, 19:05

I would be very concerned that the truck may be "making oil". It is possible that the IP is dumping fuel into the crankcase.

BugEyeBear · 10-08-2009, 19:37

Quote:

Originally Posted by BFR

I would be very concerned that the truck may be "making oil". It is possible that the IP is dumping fuel into the crankcase.

No, I don't believe that is the case, as the PO said he added oil because it was low.

He simply didn't know how much oil to add and he put in WAY too much!
(he thought it was an 8 gallon capacity, & he didn't allow for the oil to drain down to the crankcase before rechecking the level.)

The oil doesn't appear to be thinned down with gasoline either. Appears to be the correct viscosity.

It also has a fairly new looking IP installed on it.

I WILL however keep a close watch of the oil level once the existing leaks have been resolved. & if the level rises I will definitely R&R the IP.

gringeltaube · 10-08-2009, 22:48

Quote:

Originally Posted by BugEyeBear

...........................Has anyone ever overfilled the crankcase, experienced oil leaking out of the rear seal, corrected the overfill, and then had the leak stop once the proper oil level was restored?
...................................

Exactly that, YES.

.... 200 miles at 55mph on a real hot day, main seal was leaking really bad so that everything plus clutch got soaked and it started slipping ... !
Drained about two gallons to correct level!, removed inspection cover plate, flushed clutch as good as possible with solvent, drove back home normal and dry and never had that problem again.
(lesson learned and not forgotten, after almost 20 years.....!

)

G.

BugEyeBear · 10-08-2009, 23:05

Quote:

Originally Posted by gringeltaube

Exactly that, YES.

.... 200 miles at 55mph on a real hot day, main seal was leaking really bad so that everything plus clutch got soaked and it started slipping ... !
Drained about two gallons to correct level!, removed inspection cover plate, flushed clutch as good as possible with solvent, drove back home normal and dry and never had that problem again.
(lesson learned and not forgotten, after almost 20 years.....!

)

G.

THANKS!

That's what I'm hoping will be the case with mine.
I only drove it 20miles so I'm hoping that the clutch didn't get too much oil on it.

The shop I took it to has already corrected the oil level, gets the rear axle seals in tomorrow morning (from Memphis Equip), and will then verify that the rear seal is no longer leaking & that there aren't any other leaks.

KEEPING MY FINGERS CROSSED!!!

BugEyeBear · 10-11-2009, 19:55

Just wanted to update you guys on the oil leak issue.

Turns out that the PO had overfilled the crankcase by at least 3 GALLONS (not counting what had already leaked out from varoius places...)!

Oil level has been dropped to the correct level, & a leak at the base of the air pump (due to a sloppy replacement of pump; some of the old gasket was still there...) has been fixed, & another leak at the injector pump (at a loose cover plate) has been fixed.

Truck has been road tested for approx 50 miles since the repair, & I'm VERY HAPPY to say that oil is no longer coming out of the rear seal!

I have noticed that it takes significantly longer than the "1 minute" noted on the dipstick for the oil level to show as full. It seems to be at the 4qt low mark for several minutes. I let it sit for an hour and then the level was FULL on the dipstick. (Perhaps this is why the PO accidentally overfilled it!)

How long do you guys wait to check your oil level?

Does your level change from the "1 minute" reading?

IF IT DOES, how much does it increase?

I suppose that there is a chance that I'm now running 4 qts low from a true FULL, but I'm very reluctant to cause an overfill condition again.
(My rear seal is still sore from the last overfill!)

"Anyone know a good Deuce Proctologist?!?"

-Bear-

O.D. Fever · 10-11-2009, 20:03

Thats just wrong.

roscoe · 10-11-2009, 20:38

I keep mine about 1" over full when checked cold.