Automatic or manual transfer case, opinions

[RJ100]

Is there a difference between manual shift or pushbutton shift transfer cases? Which do you think is best? How many miles does your transfer case have on it? (manual or push button)

[OLDIRON69]

My buddy has a Z-71 he ordered with a manual shift and his has over 250K with no issues. It is a 2003..

[biggsteve97]

I have found that some of the manual shift transfer cases in the 99 and newer body style do not have any actual linkage connecting the shifter to the t-case. Its electronic but gives people the satisfaction of having a lever instead of push buttons. I have a 2002 Silverado with the auto trac push button t-case and 185,000 miles with no problems. I also have a 2003 Z71 Tahoe with 176,000 miles, the auto trac push button and I have had lots of annoying issues with the electronics, mostly just service 4wd soon lights and the shifter lights doing what they want though nothing major, however no issues with the T-case itself.

[RJ100]

Originally Posted by biggsteve97

I have found that some of the manual shift transfer cases in the 99 and newer body style do not have any actual linkage connecting the shifter to the t-case. Its electronic but gives people the satisfaction of having a lever instead of push buttons. I have a 2002 Silverado with the auto trac push button t-case and 185,000 miles with no problems. I also have a 2003 Z71 Tahoe with 176,000 miles, the auto trac push button and I have had lots of annoying issues with the electronics, mostly just service 4wd soon lights and the shifter lights doing what they want though nothing major, however no issues with the T-case itself.

thanks for the feedback,I appreciate it any additional information from anyone also appreciated.

[DirtyLarry]

Originally Posted by biggsteve97

I have found that some of the manual shift transfer cases in the 99 and newer body style do not have any actual linkage connecting the shifter to the t-case. Its electronic but gives people the satisfaction of having a lever instead of push buttons.

Next time you’re going to need a camera next time you see another Unicorn. A manual shift is just that…a linkage from your hand right to the transfercase. No lever that pushes a button to shift the transfercase. On the other hand, the front axle disconnect is still engauged electronically on both the electronic shift and manual shift.

Manual shift is much more durable but hard to come by as they are only found in base model trucks these days. The electric shift transfercases are plagued with control head problems, TCCM problems, encoder motor problems not to mention 7 extra lbs of wiring harness to go wrong. Get a manual shift whenever you can!

[RJ100]

Originally Posted by DirtyLarry

Next time you’re going to need a camera next time you see another Unicorn. A manual shift is just that…a linkage from your hand right to the transfercase. No lever that pushes a button to shift the transfercase. On the other hand, the front axle disconnect is still engaged electronically on both the electronic shift and manual shift.

Manual shift is much more durable but hard to come by as they are only found in base model trucks these days. The electric shift transfercases are plagued with control head problems, TCCM problems, encoder motor problems not to mention 7 extra lbs of wiring harness to go wrong. Get a manual shift whenever you can!

Thanks for the reply. I have a 99 with rusted up frame with electric transfercase and a 2000 model with manual shift transfercase with blown engine. Am trying to decide which set up to put together.

[OLDIRON69]

My '86 S truck had a manual shift but when I took it out to do a body lift I noticed it was just a big switch, no linkage..the newer with manual shift are just that.

[DirtyLarry]

Originally Posted by OLDIRON69

My '86 S truck had a manual shift but when I took it out to do a body lift I noticed it was just a big switch, no linkage..the newer with manual shift are just that.

Oh, boy….. now we have two guys that have seen Unicorns. I have been working with GM vehicles for many many years and there isn’t a single current or past production GM vehicle with a manual shift transfercase that shifts the tcase electronically. A manual is just that…. A manual shift lever with a linkage from the shifter assembly directly to the selector shaft on the transfercase.

Here are pictures from the 2011 Silverado service manual where you can see where the shift rod connects. This method of shifting the manual tcases has been used since the 80’s when GM first moved the aluminum 208 tcases. Manual shift trucks, SUVs, and S-trucks are all like this.

Here you can see the arm at the bottom of the shifter assembly where the shift linkage connects


This is how you unhook the linkage from the shifter assembly from under the truck.


After twisting wrenches to get through college I spent a few years in Detroit working in rotational roles in Chevrolet Technical Assistance, GM Brand Quality teams, Silverado brand team and Silverado technical sales before moving to the field as a service rep. When you find a bone stock unmolested GM vehicle with a lever on the floor that shifts the tcase electronically (encoder motor) post a picture with the VIN and I’ll send you $25 gift card of your choice. They don't exist!

[OLDIRON69]

It has been 10+/- years ago. I sure could be mistaken. It was an '86 S-10. What would the electronics be for then? Possibly just for shift indicator? I'm not afraid to admit I'm wrong but that is just how I remember it. Lots of beer back then too..lol

[DirtyLarry]

Originally Posted by OLDIRON69

It has been 10+/- years ago. I sure could be mistaken. It was an '86 S-10. What would the electronics be for then? Possibly just for shift indicator? I'm not afraid to admit I'm wrong but that is just how I remember it. Lots of beer back then too..lol

No problem. We're all just having fun here. One electronic connection would be the VSS and the other would be the signal to the front axle disconnect. Back then the disconnect should have been a vacuum switch. Newer trucks have yet another circuit that tells the ECM the tcase is in 4lo to adjust fuel and spark as part of torque management to prevent drivetrain damage.