oil leak in 88 2001

[mrobinson]

I noticed the other day a slight oil leak coming from where the tranmission joins onto the engine(at the bottom of the bellhousng). has anyone had a similar problem? the oil is engine oil, not transmission oil. any help would be great, thanks.

[boatech]

RE: oil leak in 88 2001

if your 100% sure its not trany fluid it could be coming from the rear main seal wich is the seal that seals the rear of the crankshaft or it could be the rear of the oil pan gasket. but most of the time a leak from there is tranny. the input shafts get rusty/pitted and cuts the frt pump seal on the tranny they sell a sleave kit for it. because the shaft cost $650.did a 87 just the other day.

[richard]

RE: oil leak in 88 2001

agree with boatech,the photo shows the main seal of GT-40,by removing the bell house,you can reach this part, and confirm it's leak or not, you can order from SKDIM, careful L & R rotation engine use different main seal when order.

[mrobinson]

thanks for your help, it looks like im going to have to take the motor out to get a better look. If it is the rear main how hard is it to do yourself? do engine hours relate to how long the seals last? because the boat only has 600 hours on it.

[boatech]

first richard as a great pic of it. you dont take then eng. out. pull the trany alot easier and will gain you access. the fact that its leaking can be caused by many facotrs. the point is if it is indeed oil you need to pull tranny and find out for sure where it is comming from. another good point made by richard is the rotation of motor. very important on the seal you get. there is a little bit of skill/faness involved if you are thinking about installing them or you will tear them. im may be best to have it done, but if you get a good shop manual and have a little bit of mechanical ability you could do it. taking the trany out is pretty easy. the trick is installing the seal without damaging it. PS. richard i like you engine stand i have one just like it!

[richard]

engine oil leak

boatteach:
I think you like tree,not engine stand,ha,.
I change my main seal by the way in my winter project last year for repair the vdrive and renew the engine , ,since I saw little bit oil wet at the lower part of the main seal. don't pull the engine out only for replace the main seal, it's not fun job!

[Texas88]

I did a rear main seal in my 88 SN. Two things you need, one the seal for the proper crank rotation and two, a speed sleeve. That is a very thin sleeve that slides and fits over the crank where the seal rides. With use, the crank gets a very very small groove that can leak and with lack of use the crank end can pit causing a small leak.

I have done lots of boat motors so I find it easier to pull engine w/ transmission and work on everything out in the open on the stand. You can get the speed sleeve at a speed shop or high end auto store, for about $25 you don't wan't to do this job twice. Don't ask me how I know.

[Andrew]

Nice windchime! :P

[mrobinson]

thanks everyone for your help, im going pull the trasmission next weekend and get a mechanic friend to do the actual seal (if that is the problem) that way i know it's done correctly. again thanks for your advice.

[mrobinson]

Just wondering if there as any difference between a marine rear main seal and a standard automotive rear main? (provided they are both the same rotation and for a 351) thanks.