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Should shop have changed rear main seal when rebuilding transmission

We just had the transmission in our 2000 Honda Odyssey with 166,000 miles on it rebuilt. We had agreed on a price and part way through they told us we needed two transmission mounts and an axle (so $600 more). When we drove the van home it smelled like it was burning a bit and we assumed some oil had gotten on the outside and was burning off. We drove maybe 50 miles total over the next two days and when we stopped we noticed the van was smoking. We drove it back to the shop and left the keys. Today they called and said the rear main seal is bad. They said they’d give us a ‘deal’ and only charge $400 to fix it since they have to pull the transmission again. We feel like the seal should have been checked or replaced as part of the rebuild. Is that a reasonable or unreasonable assumption? I’m not sure if we should just pay to fix it or if we should fight it and they should make it right. Not really understanding what is typical I’m looking for some advice. Thanks in advance!

No, the rear main seal is on the engine not transmission and is not part of a transmission rebuild. They might not have seen the leak after removing the transmission before because the rear main seal is behind the flex plate. The flex plate is not removed from the engine when the transmission is rebuilt so unless the seal was really leaking bad they just might not have noticed anything. Theres really nothing for them to make “Right”. The fact that they are willing to make you a deal on replacing the seal is a good gesture on their part. Good luck with it.


Your explanation was very helpful. Thank you!

Even if you don’t do the work, you should buy your car’s Chilton and learn what is involved with each repair you are going to pay to have performed.
I agree that the removal and replacement of your transmission (same process if your tranny is rebuilt) should not impact your rear main oil seal.

But there is no way during the rebuilding and replacement you should have incurred a $600 charge for transmission mounts. You were robbed.

It was two transmission mounts and an axle that he had extra so $600 is quite possible. I haven’t priced axles or mounts on these so I could be wrong.


While it’s not a requirement and is not part of the transmission rebuild, my opinion is that the rear main seal should be changed while the transmission is out.
Removal of the flexplate and seal installation should not take more than 5 minutes and it should be considered insurance against this kind of problem.

I’ve always replaced seals when the transmission, or engine, is out. The same would apply if doing a clutch job on a manual transmission; flywheel off and main seal replacement.
Speaking for myself, I’ve always changed the seal and never even charged additional labor for this; just the cost of the seal.

Something along the same lines could be said when replacing a radiator, water pump, or head gasket. The thermostat should be changed at that time also even though it’s technically not part of those jobs. Again, it’s insurance and cheap insurance at that.

Similiar question but should the shop have changed the transmission rear main seal if rebuilding the engine? If so, is there a bok of mechanic codes stating this? I paid almost 5k for a rebuild and had to bring it back because the same transmission seal was used on the rear and it began to leak. Any help or advice is appreciated thanks.

These days of price shopping shops seem to deliver all that is on the work order and nothing else. That’s a shame. I also made it a habit to replace the rear main seals whenever I had the transmission out of cars with one piece seals.