Hi all, I am new to the DTR and have a question which I hope you guys can help me with.

When trying to shift into 4hi while moving (anywhere from 50 to 75km/hr) I get a loud grinding noise from the transfer case. If I slow down to 20 km/hr or slow it shifts into 4hi just fine. Once in 4hi there are no grinding noises and runs good. I can shift back in to 2hi while moving with no issues at all.

I bought the truck off my dad last year and he has had the truck since new. The transfer case has never shifted into 4hi very well. The truck has never been abused or been offroad. Before I bought the truck we tried switching the t-case over to Amsoil but it didnt help at all.My dad did most of the work that has been done to the truck but neither my dad or I know anything about transfer cases.

Thanks very much in advance for your help.
Andy

 

check you vacuum lines for a leak My 01 will shift in and out at any speed . also are your tires the same...all 4 need to be the same size you cant run 2 new ones and 2 old ones that will make the drive lines spin at diff, speeds.my .02

 

They may be rated to shift at any speed, but the slower you are going, the more kind you are to your transfer case. Remember, to shift at high speed, the gears need to get up to speed to actually do the shift- the faster your going, the harder it is.
If you need to shift into 4WD at high speeds on a regular basis, I would get rid of the vacuum disconnect, and install a permalock. This is a plate and shift arm which has the front axle engaged at all times. Then, when you shift, everything is already up to speed.

 

All 4 tires are band new last year and I only run them during the winter. I will have to have a closer look at the vacuum lines. I had a quick look at them the other night just to see if any of the lines were disconnected but didn't find anything.
Could the syncronizers in the transfercase be shot? I have also read something about snap rings missing on the output shaft causing shifting issues? I'm just looking for ideas on what it could be before I either try and tackle this myself or take it to a transmission shop.

Thanks your your help though
Andy

 

I find by backing off the throttle a little and keeping a constant pull on the 4X4 lever and not just trying to crash it into 4Hi the vacuum actuator engages and the gears become the same speed making the shift smoother. I often shift into 4Hi at 80kph with no problems. The transfer case needs ATF fluid

 

I'll give that a try next time I have the truck out. If that doesn't work I may just take the truck to a transmission shop.
Thanks.
Andy

 

would like some more info on the setup please.

i also have no isues shifting in at high speeds. i use the constant pressure method while staying off the throttle as mentioned above.

 

by the book you supposed to be able to shift into 4hi up to 80kms per hour. there is a blocking ring on the shift mechanism. so at that speed pulling steady on the lever rides the blocking ring and gets the front output to come up to speed. then it will engage.


I used 4hi often in my '98.5 when the highway got dicey.

 

just ease into 4x4 have your hand on the shift and start to move it you will see it will engauge alot better then just slaming into gear. IMO i wouldnt shift into 4x4 above 60km just to save the transfer case it does make a slight grinding noise above that.

 

Reading this thread I think the key is backing off the throttle before engaging 4x4.... and of course, engaging with slow, steady pressure.
I have always done so instictively and never had a problem at any speed.... usually under 80 kph.

With the CAD, It is important to engage the 4x4 regularly, when it's not used much.
I make sure to hit a dirt road and engage 4x4 at least once a week to keep everything in the front end coated with gearlube!
When I forget this exercise, 4x4 engages much harder!

RJ

 

I usually slow down to undere 30 MPH and haven't had trouble. I've never been comfortable shifting a heavy truck into 4x4 at speed. I feel its safer to slow down and shift or just get off on a ramp and shift it and re-enter the roadway in 4X. Just my .02

Kurt

 

Hmm... I can't find anything on it now. 4x4 Posi-lok also made a product called the perma-lok, which was a setup which held the collar in place, linking both axle shafts, and a plate to seal the opening where the CAD went. It was the same thing as the Posi-lok in the locked position, which is how the new trucks run. Both shafts turn all the time, the dif turns, and the drive shaft turns. You simply engage or disengage the driveshaft.
On Jeeps, some folks would remove both shaft segments, install a full size shaft from an axle that wasn't CAD, and then make a blocking plate for where the CAD went. Either way, you are just simplifying things.
Some folks might not like this, and that is fine. But, most all modern day 4x4's have done away with axle disconnecting, and just have everything up front turning. It is questionable how much this hurts your fuel mileage, and so what if it wears? It doesn't wear any more than the rear axle and driveshaft. In the grand scheme of things, to me, simple is better in comparison to complicated and a few bucks saved on fuel or parts. It is all going to wear out sometime.
Well, I have chased that rabbit enough. To answer the quote, there was a product called perma-lok, but it isn't showing up on searches now. Perhaps you could email the maker of the 4x4 Posi-lok, and find out more details. I do know it was out there.

 

My transfer case seems much better shifting once I filled the transfer with dextron+4. With standard dextron I got much more grinding at speed.

 

good luck. I had mine back to the dealer 4 times after i bought it. It was a dealer i don't care much for. But they had the truck of my dreams. They never got it fixed. They tore the transfer case apart a couple of times. Before the last time the mechanic told me to grind the heck out of it so he would have to replace everything in it. So i did, and he did, but it's still the same. Don't matter if i let off on the throttle, keep steady pressure with the throttle , or what i do. I've had it for 5 years now and just lock in at a stop or slower than 15mph and it fine. The system set-up sucks in my oppinion. But, at least i don't have to get out and lock the hubs in. Although that never bothered me, i am sure there are those few times getting out to lock the hubs in would suck. I always locked the hubs in and left it in 2hi until i needed it if i was going to do something that may require 4x4.

 

How modern are we talkin? like last few years or last decade?

Ill be lookin into that posi lock, I seem to be havin strange 4x4 ingadging lately.
Good thread.

EDIT.. http://www.puredieselpower.com/catal...t-p-25236.html

This is what we're talkin about right?