UA80-MH-VST

The kit is designed for repair and modernization of the AWF8G45 transmission, the purpose of which is to solve the problem of combustion of the K1 Clucth clutch drum, when driving on the highway in cruising mode in the range of 6-7-8 gears.

Why does the K1 Clutch drum keep burning out?

To better understand the cause of the problem, let's look at the design of the C1 Clutch drum that Aisin and Toyota engineers used to support the C1, C3/C4 drums.

In the European version, the C1 drum is supported on the input shaft via two supports - a radial needle bearing and a plain bearing.

In the American version UA80E/F only on needle bearing.

Both options work reliably if and only if the lubrication system pressure does not exceed critical values.
A multiple increase in the lubrication system pressure is a problem with the hydraulic unit. At the same time, all switching and operation of the torque converter are normal and nothing indicates a problem.

And it is expressed in the penetration of the oil stream through the lubrication channel and then through the Teflon ring under the piston C1. And the bronze bushing helps the liquid to go only under the piston. Therefore, Toyota engineers, knowing about this problem, made one support at the drum C1.

The support on the bronze bushing in the C3/C4 drum also reaches 100,000 km with great luck, but this is the topic of a separate article
So, by changing drums C2, C1, input shaft from ua80e/f we avoid compression of the C1 package on 6-8 gears.

Through experience we have developed this kit, which solves the problem of "all time burnout C1 Clutch".

The UA80E/F input shaft, after cutting off the plastic ring housing, locking the torque converter, and removing one of the four plastic rings at the base of the shaft on the front, functionally becomes an 8G45.