March 2011 Archives - Transmission Digest
Ford’s Hybrid Transaxle – Part 2

In part 1 of this article last month we ended with the transaxle sitting on the bench awaiting disassembly, so let’s disassemble. You will notice in Figure 1 that we are ready to remove the top pan; we can’t call it a valve-body cover because there is no valve body.

Don’t Get Shook Up

Here is a trouble vehicle – a 1999 Chevrolet 4WD Silverado extended-cab pickup – suffering from a problem whose unique cause was difficult for us to find. The customer’s complaint was that the transmission-to-transfer-case adapter had cracked repeatedly. I don’t know the exact count, but by the time we were blessed with this job I think the count was three broken adapters. Figure 1 is an example of one of the broken adapters that was cracked near the transfer-case mounting bolts.

New Transmission Technology Already Here, and More Coming

The old saying “The only thing that is constant is change” has never been more true than in today’s automotive manufacturing. We have seen the bankruptcy of Chrysler and General Motors, which 20 years ago was unthinkable. China has arrived as a manufacturing giant for all types of products and, with a billion plus people with rising income levels, is poised to become the largest new-car market on the globe. India and Brazil have leaped ahead economically and will become players in this market.

Many Happy Returns

Since so many previously dedicated transmission-rebuilding facilities have of late become more oriented toward repairing and servicing the entire vehicle, a new set of challenges has emerged. Leading the pack, believe it or not, is returns – parts and cores that need to go back to local parts stores for credit to the shop’s account.

Serviceability Report: BMW

You, the technician, need a voice of reason. This article completes eight years of reporting on the basic construction of different carmakers, but we have never looked at BMW.

BMW is one of three car companies that make motorcycles; Honda and Suzuki also make motorcycles. Each company has a history of racing. At the track, making the car or motorcycle hard to fix is the wrong way to go. All three of these brands are well respected in reports on their two-wheeled machines, but how do American technicians view the four-wheeled BMWs?

Why Resistance Checks Don’t Always Work

The example used here is a 1998 Oldsmobile Intrigue 3.8L with a 4T65-E transaxle that has a P0753 electrical code – 1-2 shift solenoid circuit – stored in the PCM; no other DTCs are present. The code will not set until the 1-2 solenoid is commanded to turn on. Now we have all seen the diagnostic flow chart for this code. No matter which repair-service publication you use they are all basically the same: Check resistance from here to here and here to here, from there to there and from here to ground, blah blah blah; I think you know what I mean. Then we print off a wiring diagram so we know what to look at.

Close but No Cigar

The design of the OD planetary system in these transmissions allows for a 1:1 ratio from the input shaft to the center shaft until the overdrive band comes on and holds the sun gear. When this happens, the input shaft will spin slower than the center shaft.

Walking the Thin Line

The late-model 518 is a prime example of this statement. When we get OE cores, the covers measure 0.160 to 0.165 inch thick if they are undamaged. The front covers can normally be cleaned up by machining off 0.005 inch of material. The challenge comes when we get a cover that was galled or damaged by a major lockup failure. In these instances, you may have to machine off as much as 0.015 inch, and at this point you end up with a cover that is only 0.145 inch to 0.150 inch thick. The question is, how far can you go? Where is the line between thick enough and no longer thick enough?

March 2011 Issue

In This Issue
45RFE • 545RFE
Dodge trucks: DTC P0715 and/or slow PRNDL response
45RFE/545RFE: Pulls forward in neutral
Jeep 545RFE: Misleading codes