1994 Landcruiser Prado rough start problem with fix (1 Viewer)

[Contendi]

We just got the Prado back from the mechanic and I wanted to report the issues and the fixes in case someone else has this problem. 2nd day driving it and it's a blast. The throttle and clutch feel a lot more responsive and torquey. I'm able to hit 5th gear now like it should (I was getting crappy mileage running it in 4th most of the time). Lastly, no more rough hot start issues!

1994 Landcruiser Prado 1kzj78 manual transmission, 209,000 km, 2nd or 3rd owner, located in Okinawa, Japan.

Issues:

• After the engine was hot/running for more than 10+ minutes and turned off. When I started it back up, the engine would shake violently, a lot clatter could be heard like it was starving for something, possibly thought a starter issue, and the engine would take an extra second to begin running normal.
• Cold starts were always fine, so we thought maybe something was expanding and causing the problem
• 5th gear didn't have the power it should have. My friend has an identical manual Prado and his 5th gear could pull and cruise as low as 1200-1300rpm/40-50kph while mine was bogging and vibrating the truck.
• I replaced the starter with a rebuilt one, and noticed a lot of gunk in the bellhousing. Folks here and on ih8mud helped me identify a rear main seal leak. Possible friction between the clutch plate and flywheel when it wasn't supposed to could have caused that clutch dust to mix with the oil leak and allow it to partially solidify.

Fixes (took the truck to a friend of a friend's shop):

• After trying our best to translate with my friend who speaks English and Japanese, the mechanics were pretty sure the oil leak was causing the issues above.
• They recommended new flywheel and clutch because they appeared to be impregnated with oil. They also noticed the heater core pipe was rusting and wanted to replace while the transmission was out.
• Truck was down for 3 weeks while they located the flywheel from a supplier who got it from possibly Pakistan or UAE area where the trucks are still widely utilized. This was the hardest part to find new.
• Complete parts replaced: flywheel, clutch, pressure plate, throw out bearing, heater core pipe, and rear main seal
• Total price for parts, labor, and the loaner van was $2000/275000 Yen with the exchange rate.

 

[ATL Cruiser]

I understand the rear main seal leaking all over the clutch causing severe slippage.

But how did that remedy the hard start after a hot soak issue? Are the technicians stating that the rear main seal caused a rough start? That seems odd.