I'm hoping someone out there has some insight on this issue. I've got a Volvo A25D that is filling the bellhousing with engine oil after a few hours of operation. Rear main seal and the seal between gear case and bellhousing have been replaced, but issue persists. Pulled the starter this morning and oil was running out. Went ahead and replaced the power take off lube/drain pump as well since it didn't seem to be pumping oil out of the the pto gear case that is bolted on the bottom of the bellhousing. Ran the truck awhile and checked engine oil, found it very low. Pulled starter and of course bell housing is full again. Its not making a whole lot of sense to me, hopefully somebody has a lot more Volvo experience than me
I think the 25d's have a scavenging pump in the bell housing, I know the 35's have that. Hope this helps.
You say you have replaced the rear main seals, did you check the gear that the seal runs on? this gear has a habit of getting a grove run into it where the seal runs, at which point it doesn't matter how new the seal is, it's just going to leak past. that or it could be leaking past the o-rings on the gear to the side of it.
There is a scavenging pump that drains oil from the gear case. I checked the old one and found it wasn't pumping. I replaced it but it didn't change the symptoms, today I'm going to check all the lines for obstructions to make sure the oil has somewhere to go
We checked that gear when we had it apart, and it may have had a hint of a groove forming, but it didn't strike me as being an issue, but I'll certainly acknowledge that I may have misjudged. Its transferring a lot of oil to the bellhousing in a relatively short time, we ran the truck about 4 hours after we did the rear main and then pulled the starter and found bellhousing completely full of oil
it's not very often that the scavenge pump fails, so I would check the pipe work from it, other than that i'd look closer at the gear, the little gear to the side, the o'ring on that keeper plate etc, also be aware that the engine oil if it gets to high can go into the transmission.
did you check the scavenge pump pick up screen
I wouldn't imagine that pump fails often, after we did rear main we pulled the scavenging pump as I suspected it wasn't clearing the oil from the gear case. We ran a line into a reservoir of oil and spun it with a drill, got no output from pump so we replaced it. Afterwards I ran the truck around a couple of hours, then pulled engine dipstick and saw oil was low. Pulled starter and found it in the bellhousing again. We checked plumbing from pump to motor today, all seems to be clear there. This thing is starting to give me fits lol.
Yes, screen was plugged up when we started this project, it was initially what I thought was the whole problem. It was one of the first things I looked at, but cleaning it didn't help our issue any.
When you did the "drill test" on the scavenge pump and condemned it as producing no flow, did you by any chance perform the same test on the replacement pump before installation.?
The only way for the oil to get to the PTO unit is past the PTO housing, so its either the crank seal or the O-rings on the idler shaft or a crack in the PTO housing it's self, there are a couple of different updates on the O-rings on the idler shaft and on the crank seal so I would suggest revisiting that area again. In all the time I have been doing this job I have sold maybe 3 scavenge pumps, probably three times as many crank gears and god knows how many speedy sleeves for those that try the cheap fix, and tens of hundreds of crank seals and idler gear O-rings.
I did not perform same exact same test on new pump, however with new pump installed and truck running I did crack open a banjo fitting on the output side of the pump and had good flow at that point.
Yea, I'm coming to terms with the fact that I may have to pull it back apart and examine everything once again, it is what it is lol. Is there any chance you can get me part numbers for the updated seals and O rings? I want to make sure I get the right stuff and my Volvo dealer is often less than helpful On another note, I want to thank you guys for your help, it is greatly appreciated. I've lurked around here for a long time and its a helluva resource
ok so the new O-ring that goes in the seal cover on the crank shaft should be 990249 was 943302 and the new O-rings on the idler shaft should be 977015 was 925092 they should be supplying the new parts as the old ones have been superseded for a while now.
Well, just an update. Engine is back in the truck and we're not losing engine oil anymore. That's a win!
What was the solution