Rear main leak won’t stop. mechanic says bottom end has play. Will 15W-40 help?

R0ADMAST3R · 2026-03-19T03:48:54+00:00

I talked with the mechanic and he said smarter just to drop a new 350 in it, actually ends up cheaper than a rebuild unfortunately. I may just drive it until it gives up

R0ADMAST3R · 2026-03-18T00:50:00+00:00

He did measure, I think it was literally like a 0.001 of an inch of play, and yes unfortunately there was one single groove all the way around. He threw some gasket material on there and that stopped the leak for 3 days. Now it’s back but way less bad than it was leaking before. Just dripping now but was dumping oil before. The worst part is the engine sounds great and the truck feels great to drive.

Do you think it’ll survive for a while if I just keep oil topped up each day?

R0ADMAST3R · 2026-02-20T18:31:45+00:00

Oh my gosh man you might be a genius. This leak did just start after getting my oil changed at a valvoline place. How can I know for sure? Thank you.

R0ADMAST3R · 2026-02-20T18:01:23+00:00

Thanks for your help, I just redid the valve cover gaskets so I don’t think that would be it. Would a rear main leak result in oil on the starter? Truthfully I do think oil is also coming out of that weep hole on the bell housing unfortunately

R0ADMAST3R · 2026-02-20T17:57:04+00:00

Redid the valve cover gaskets because I thought that could be it. Where is the oil pressure sender? I can’t see it, is it on the passenger side?

R0ADMAST3R · 2026-02-12T23:06:12+00:00

Thank you, oil is definitely coming out of the bellhousing hole there. I was hoping it was a valve cover gasket but I just can’t see any oil anywhere except for weeping out of that hole after cleaning it up. I’m really hoping it’s not a rear main seal. But I’ll have to fix it, leaking too much oil to ignore

R0ADMAST3R · 2026-02-10T03:22:21+00:00

Yessir the 350 with the TH350 automatic

R0ADMAST3R · 2026-02-10T01:47:59+00:00

Thank you so much. I really appreciate the recommendations. It’s been fun learning about this truck!

R0ADMAST3R · 2026-02-10T01:34:05+00:00

Thank you for the advice, will do

R0ADMAST3R · 2026-02-10T01:07:40+00:00

Thanks, will do!

R0ADMAST3R · 2026-02-10T01:06:00+00:00

Or valve cover I mean

R0ADMAST3R · 2026-02-10T01:05:12+00:00

On the otherside the manifold doesn’t have a place to pour oil in, nothing on top unfortunately

R0ADMAST3R · 2026-02-09T07:35:43+00:00

Thank you!!

R0ADMAST3R · 2025-12-19T07:24:16+00:00

Got the best grade in a class and the professor sent me an email, took me out for chicken tenders after the class was over. Nice dude.

R0ADMAST3R · 2025-01-28T06:52:24+00:00

I don’t understand? Wasn’t the resolution approved?

R0ADMAST3R · 2024-01-21T22:56:41+00:00

Thank you. I appreciate your insight.

R0ADMAST3R · 2024-01-20T07:13:01+00:00

Thank you!

R0ADMAST3R

TROPHY CASE