Rolls-Royce / Bentley 6-Way Adjustable POWER SEAT GEARBOX 1986-1987.5 UB39167 RY



Years: 1986-1987.5  Part No: UB39167 RY
The same unit is used on both the driver's seat and passenger seat. These units are the same for both RHD right hand drive and LHD left hand drive.

Proper Parts has re-engineered the housings for these units.
Our new transmission housings are manufactured in the USA from extremely durable polyamide with fiberglass fill and are Guaranteed for Life. The internal components are reconditioned and Guaranteed for 5 Years. The complete unit is assembled, tested, and shipped to you ready to be installed.


After installing your new unit, ship your old unit (core) to Proper Parts to receive your core refund. Your purchase receipt must be enclosed to process your refund. 

Please do not ship your core until after you've finished installing the new one in order to avoid sending parts that you'll need to keep for installation.

We ship within 1 to 2 business days.

Please return your core within 30 days. After 45 days, a late fee of 10% will be charged. Your core refund will be credited to your original payment method when we receive your core in acceptable condition. 

What is an acceptable core?

If the outer case is broken, that is not important. The internal components are what is important. If there are missing or damaged internal components, a pro-rated refund may apply. If you have any questions, please contact us in advance. You can send photos and we'll give you a quote for the core value.

Just because your core is badly broken and in pieces, does not mean you will not receive a full core refund. We just need the internal parts.


Black, Red, and Yellow Input Shaft

The original transmission housings were made of nylon. They were white when new but became brown and brittle over time, and many have disintegrated. Most failures are due to the housing breaking apart. There is no new OEM replacement available for this part.

Rolls-Royce and Bentley used the same part number UB39167 to cover two different parts. You can tell the difference by looking at the color of the input shaft. This transmission had a red or yellow input shaft, not a black one. It used a white plastic coupler. It was mounted to the motor with a 1/8 inch aluminum spacer plate between the two.

If the coupler is tan, brown, or anything other than brilliant white, we recommend replacing it. If you would like to add it to your order, click the link below. These couplers are new aftermarket, and they require a bit of force to install. Please install to the transmission first, as far as it will go. 


New aftermarket white plastic coupler

Please note: Power seat components are designed for normal use. Please move the seat to the desired position and leave it. Repeated up and down or back and forth movement without several minutes to cool down will produce damage. 

Instructions for shipping your core to Proper Parts:

  • Your receipt must be enclosed to process your refund.
  • Ship to: PROPER PARTS, 5725 HARRISON AVE, EXPORT PA 15632.
  • You are responsible for return shipping on your core.
  • Email tracking number to:  

If you have any questions, please contact us.