Lubrication Archives - Transmission Digest
Leading Causes of Manual Transmission Failure

The most common reasons a manual transmission failed are lack of lubrication, incorrect lubrication and improper or no clutch release.

5R110W Lubrication Concern (Warm weather – no problem, but winter’s coming)

We all know that certain transmission models exhibit problems based upon temperature levels. Most of the time, heat is the overriding factor, but in this installment of Technically Speaking, we’re going to look at models which are more susceptible to cold.

Later-model 5R110W transmissions could fit into this cold-temperature column; however, it would be prudent to inspect any 5R110W, regardless of the model year. When Ford launched the 5R110W in 2003, a unique cooler-line filtration system was developed and used for several years. Instead of a normal inline filter that merely splices into the pressure or return cooler line, the 5R110W used a bypass filtration design.

No Rear Lubrication

A JR403-E transmission from a 1995 Isuzu NPR came in over the counter to Luis Zabala’s transmission shop in Miami for repair of a front-seal leak. The unit was examined for damage because of the possibility of low-fluid-level conditions. The only wear or damage discovered was the pump bushing and seal.


One of the things often neglected is lubrication of the transmission, transfer case and differential. As with the automatic transmissions there are now dozens of specified lubricants that a professional shop must have available. What used to work no longer does, and putting the wrong lube into a late-model unit will result in spoiling a good rebuild. You must use the correct fluid for the unit you are working on. It sounds logical, but if you understand why, it will go a long way toward preventing shift complaints and outright failure under warranty due to incorrect lube fill.

Repeat Catastrophic Lube-Related Failures

Most transmission technicians who work on rear-wheel-drive Chryslers are all too familiar with the devastation associated with poor lubrication. Galled governor supports, galled and/or seized output shafts, or rounded sun and planetary gears are all common failures (see Figure 1). Although towing a vehicle with the drive wheels on the ground will yield the same results, the vast majority of failures are caused by a simple lack of or insufficient lubrication.

It Ain’t Just Oil

One thing we have seen that is consistent in the repair industry has been an unprecedented explosion of new and changing technology. An amazing number of new transmission and transfer-case designs soon will be appearing in your shop. The ever-increasing use of computer and electronic controls has made all the units more sophisticated, and diagnosis is becoming a stand-alone specialty.