E38 / E39

Metal Window Regulator Wheel Kit

$240

Replace the cracked plastic wheels in your E38's window regulators with our 6061 Aluminum replacements.

Includes: 12 Aluminum wheels, 12 press fit ball bearings, 12 hollow threaded rods, 24 nuts and washers, and detailed instructions.

Details

Attention! This product is a group buy! Once we hit 250 wheels ordered (~20 full car kits) you will receive a confirmation email and manufacturing will begin. If we do not reach this goal by 11/1/26, all preorders will be refunded. Please feel free to reach out to tb@forestwinder.com with any questions.

E38 window regulators have a fundamental flaw. The cable rides on plastic wheels, and over time these wheels crack and decay. New genuine window regulators have reached $400 (without the motor), and aftermarket units have mixed reviews. Instead of replacing your whole regulator, you can simply replace the part that's broken.

Our kit includes everything you need to replace the plastic wheels in your regulator. Each front regulator includes four wheels, and each rear includes two. The wheels are machined from 6061 Aluminum, and feature a press fit ball bearing to minimize internal friction. Also included is a custom hollow rod, as well as the washers and nuts needed to create a better-than-oem system. The process is simple: drill out the old rivet, remove the plastic wheel, slide in the metal one, and secure with the custom hollow threaded rod.

I am not the first to do this! Bimmerforums user Dville sold window regulators with the metal wheels installed from 2016 to around 2018. I wanted to clarify that the design used in this kit is different, and that I am not affiliated with the original group buy. The original design did not use a ball bearing.

FAQ

How does a group buy work?

Group buys allow someone to offer a product to a group without the risk of buying the materials up front. The individual cost to produce each kit depends heavily on how many wheels, bearings, or rods, are ordered at once. By offering the product as a preorder, I can set the price based on the cost given a certain order quantity, and offer the product only if the quantity goal is met. In this case, the goal is 250 wheels. If the goal is not met, all orders will be refunded. This protects me from ending up with thousands of dollars worth of unsold parts sitting in my house, and allows me to offer the product at a much lower price than if each order was a one-off production run.

How long until they ship?

Unfortunately, I can't promise an exact shipping date. On 11/1/26, materials will be ordered and manufacturing will begin if the group buy goal is met. If not, all orders will be refunded. I am confident I can have all kits prepared, shipped, and delivered before the end of the year.