Fixing Our Leaking Transmission

About a year ago we set out to do the most complicated mechanical thing we have ever attempted on our bus by ourselves: repairing the transmission leak that had been getting worse and worse. The bus has always had a small transmission leak but it was finally to the point where it was embarrassing to park the bus anywhere. Transmission fluid ended up all over our tow car, all over the engine compartment, all over the rear of the bus, and to make matters worse the fluid is very expensive. It cost about $55 per gallon and we were going through about a gallon every couple of weeks.

Of course, we tried to do the easy things first. We pressure-washed the engine to see if we could spot where the leak is coming from. Perhaps it was just a loose bolt? Maybe if we just tighten all the bolts up nice and snug it would stop leaking or at least slow the leak down to a more manageable level? NOPE! To make matters worse we ended up breaking a bolt right off as we were trying to tighten it.

To add insult to injury: the bolt cannot be removed without completely pulling the transmission off the engine because it is too long and makes contact with the oil pan on one side and the transmission pan on the other side. ARRG.

Here is what we know: The transmission itself weighs close to 1000 lbs by itself. It holds close to 7 gallons of transmission fluid. In order to pull it we would need to completely drain the coolant as well as all the transmission fluid from the transmission and from the bell housing. We called around the Phoenix area to see if we could get anybody else to do it for us and came up empty-handed. Of course, COVID going around did not help but in general, getting someone to work on these old buses can be very challenging.

We spoke to Scott the bus grease monkey and he convinced us that we could handle this job. He walked us through the exact procedure, gave us a few tips for the trickier sections, and guided us as we attempted to finally get this transmission leak under control.

The job was grueling. To make matters worse, Juan ended up with COVID and it hit hard right as we started the project.

In the video, we walk through every step we took to pull the transmission off, fix a thread that let loose on the transmission with a thread repair kit, apply the new seals, and get everything back together.

We have been on the road with the repair for about a year now and while it does still leak a little bit - it is still a huge improvement over the condition it was in prior to resealing it.

Watch the video: