Rear seal leaking oil. Help

[Raquin]

I just bought a Ericson 39. 4108 Perkins. Owner told me the motor was rebuilt less than a year ago. New paint. Looked like it. Went for a sea trial yesterday. The motor oil poured out, by the looks of it, out the end of the tranny. Felt like the tranny was slipping had very little forward propulsion. Had to sail to get back home. 3 hours of motoring. Does this sound like rear main seal. If so how many man hours would you think to replace it. Plus should something be done about the slipping tranny or was that do to all the oil. Thank you for input.

[nhschneider]

The rear seals on the Perkins 4-108 are very difficult to install correctly. The block must be turned upside down for proper installation. Sorry, but I can't think of any way to fix this short of removing the engine and replacing the seal. Perhaps others will post easier solutions.

Fair wind and calm seas.

[model 10]

The engine rear seal would have nothing to do with the trans. If you have a Paragon trans for example, it also uses engine oil. Oil pouring out , no go, maybe it's not that rear seal. You hope? My trans input shaft is badly pitted and needs to be replaced, much more $$ than the engine rear seal. Both suck!

[AnchorageGuy]

The rear seal on the 4-108 is problematic and if not redone correctly can leak worse than before. But this does not affect the transmission. You need an engine survey by a qualified mechanic, not a surveyor, and not try and make the decision based on postings here since none of us can see first hand what's going on. Chuck

[gordwedman]

I have a Westerbeke 40 which has a Perkins 4-108 block and I asked an experienced mechanic how you change the rear seal and he said nothing about taking out the motor and turning it upside down. Parts4Engines, a UK distributor of Perkins 4-108 parts has an improved sealing material, basically a teflon impregnated rope, for these engines and could be contacted about installation.

[onestepcsy37]

racquin, did you buy it or just sea trial it?? if just a sea trial, i'd pass on it unless you can find a real perkins mechanic to look it over and give you a cost estimate. might not be the engine seal, might be the transmission (although my tranny - a velvet drive - uses automatic trans fluid, not engine oil).

by the way, my dock neighbor pulled his transmission out and replaced the rear engine seal on his 4-108 with his boat in the water. took him a few days, mostly setting up the block and tackle arrangement to lift the tranny out...

[gjordan]

Did you check the dip stick for both the engine and tranny after the motor home? If one or the other is low, it will give you a clue as to the problem. Once the fluid is mixed with bilge water, it is hard to determine what it was. Very few installations have the motor oil as the tranny fluid. ____Keep us posted____Grant.

[gjordan]

Raquin, what type of transmission do you have?_____Grant.

[Raquin]

I made a commitment to buy the boat. Paid half down. Motor looked like it had been rebuilt. Before I went out I checked the motor oil nothing on the stick. Put three quarts in. That should of been my first indicator. As I was motoring threw the bridges I noticed I was losing head way. Even thought the motor sounded good and strong. When I got to the inlet I killed the motor and went sailing. Motored just a little more that night to get to a anchorage for the night. In the am I couldn't find where to check the tranny oil but the motor oil was off the stick again. It looked like it was coming out the tranny but could just be the level in the bilge on the shaft. I am heading to the boat tomorrow and going to get a mechanic to advise. Thanks for all the input. I just joined this site. All good so far. It was strange to me that loss of head way with the diesel sounding strong. If I keep the rpms down we would make better way. I wondering if I have two unrelated problems. Thanks again for all the input. Grant I dont know what tranny it is yet.

[charliehows]

Originally Posted by onestepcsy37

racquin, did you buy it or just sea trial it?? if just a sea trial, i'd pass on it unless you can find a real perkins mechanic to look it over and give you a cost estimate. might not be the engine seal, might be the transmission (although my tranny - a velvet drive - uses automatic trans fluid, not engine oil).

by the way, my dock neighbor pulled his transmission out and replaced the rear engine seal on his 4-108 with his boat in the water. took him a few days, mostly setting up the block and tackle arrangement to lift the tranny out...

not sure if this has come up elsewhere but - pulling the engine whilst on the boat can be a very useful procedure and its not much different to doing it in a car - except the access problems. I pulled mine by mounting a box section lifting frame and block/tackle across the sides of the cockpit - put a bit of strategic timber reinforcing underneath - and drilling a hole through the cockpit floor, run in some 6mm cable, pulled the engine off the mounts and turned it sideways, put some timber supports underneath it so i could get the gearbox off - thats what i was fixing so didnt need to do anything to the engine that time.

[Raquin]

The motor stopped leaking. I guess it sat for some time after the motor had been rebuilt. I think the greased rope main seal dried out. That is why the oil was pouring out. Now it has stopped.

[onestepcsy37]

reminds me of a very long article i once read about emergency medicine. it had been written by a sailor/doctor and offered much and varied advice on what to do in many situations that might arise at sea. unfortunately it advised using drugs/devices not readily available to the average boater. but it ended with this bit of useful advice;

'it's good to know that, if you are unable to do anything to help, most ailments will cure themselves, given enough time'.

sounds like what happened to you....

[captain ray]

In the VI with perkins - used Jiffy sleeves(sp) common to truck re-build in the US. Talk to a truck repair facility -- captain ray