Engine/Transmission (1998.5 - 2002) 3.54 or 3.73 or 4.11?

[TDIdog]

I'm thinking of changing gear ratios. I currently have 3. 54 & find the temps will come up when towing in the mountains. I was thinking of going 3. 73. I know its not much change, but I think it might be enough. Has any body changed from 3. 54 to 4. 11 and wish that they had 3. 73? 4. 11 just seems a little low for cruising around empty. I would appreciate any input. My truck is a 2001, DTT, DD2s, Comp(no wire), PDR HX35/14, 265 tires, 4x4. Thanks



jack

 

[EBung]

I personally dont think you can get better than 3. 54 with stock tires. If 65mph is your speed of choice then go for it.

 

[Mundgyver]

Are you talking rear end temp or engine temps??? I have 3. 54 and the hottest I see my rear end get to is 150* and that is towing with a 4,000 lb trailer with 16,000 lbs loaded on the trailer for a total of 20,000.



Do you do allot of towing??

 

[SnoKing]

I'm thinking of changing gear ratios. I currently have 3. 54 & find the temps will come up when towing in the mountains. I was thinking of going 3. 73. I know its not much change, but I think it might be enough. Has any body changed from 3. 54 to 4. 11 and wish that they had 3. 73? 4. 11 just seems a little low for cruising around empty. I would appreciate any input. My truck is a 2001, DTT, DD2s, Comp(no wire), PDR HX35/14, 265 tires, 4x4. Thanks



jack

Jack, we have similar setups. I tow a 12K 5th wheel, and would not trade my 4:10 for anything else. Run most freeway hills in OD and have lots of power in 3rd for mountain passes. With the 14 exhaust housing are you able to light the turbo up? What kind of boost are you seeing on a good hard pull?



If you go to 4:10 and find them to low, then setuup the tires a few sizes.



Hardly worth the cost to only go to 3:73. BTW with 4:10's 2000RPM is 64-65 miles per hour.



SNOKING

 

[klaybus]

Jack, we have similar setups. I tow a 12K 5th wheel, and would not trade my 4:10 for anything else. Run most freeway hills in OD and have lots of power in 3rd for mountain passes. With the 14 exhaust housing are you able to light the turbo up? What kind of boost are you seeing on a good hard pull?



If you go to 4:10 and find them to low, then setuup the tires a few sizes.



Hardly worth the cost to only go to 3:73. BTW with 4:10's 2000RPM is 64-65 miles per hour.



SNOKING

Thats a fact! I wouldn't waste the money on 3. 73s. I just went from 3. 5s to 4. 10s & I now have a new truck! Most cruising while pulling a #8500 5vr, 16k CGWR is done in OD. Like Snoking stated, lots of power in 3rd direct if needed. Yep, higher RPM's though... 3. 73s aren't significant enough of a change to spend the money on a R & P change. 4. 10s seem about perfect to me. As a matter of fact, I dumped my 295 BF Goodrich tires & went down to 265 Michelins & even went a touch lower on the end ratio.

If pulling is what your interested in doing with your truck, 4. 10s is your answer. Period!



JMHO,

Clay Oo.

 

[SnoKing]

Clay, not to change the subject, but we are now in Colorado Springs, Co and I am very happy with EGTs with the PDR35W12 Turbo. I did turn the boost elbow up a little, and could most likely turn it up some more, as I am only pushing 26-28 towing the 12K 5th wheel. SNOKING

 

[klaybus]

Awesome! Thats what I was hoping to hear. I recently replaced my VP & tapped the pump wire at that time. PDR-35 is next on my list of mods & then a set of Dons 1. 6s. Glad to hear it's getting the job done!



Clay

 

[TDIdog]

I only tow occationally about 8-9k lbs, but when I am, the sweet spot is about 75 mph @ 2000rpm. It's great except when I get in the mountains. If I had a switch that could get the transmission to unlock, that would help. The trouble right now is it locks up and I have to come to just about 20mph bfore it unlocks. I did have a 12 housing on my PDR35 & think it spooled betterdown low, but top end wasn't as good. Might have to change back. Was thinking of going a little bigger trailer, so want to get the truck dealt with. Thinking of going to DDP3s & tapping the wire, I think that should help fire up the turbo. I do tow now in OD, but I have to be cruisin. I just thought that 3. 73 was a good all around ratio, but think I will try dealing with the transmission first. Thanks for you inputs.

 

[TDIdog]

PS, Right now I can get about 32 psi max. When I installed the 14 with wastgate, it wouldn't go over 32, & thought it diconnect it to see if I could get it higher ,but thats it. When I'm towing & I go into third & get it up to around 27-2800 rpm the temps start to come also. Thanks again for your help.

Cheers

jack

 

[Bunyan]

What rpms are you getting at 70mph with 4. 10 gears? I also have 3. 54s and want 4. 10s. Just want to know what the rpms get to at 70. Seventy is the posted speed in most places I travel here in Tx. Bunyan

 

[BWagnaar]

My truck is about 2100rpms, it does sound like the motor is spinning harder though. Anything under 2000rpm it sounds like its not even breaking a sweat. I do a lot of commuting and the 4. 10 kind of suck. But when it comes to hills i live around and when i tow, nothing beats the 4. 10s esp with a stock truck. I wouldn't want to unlock the converter as much as possible cause that would build up transmission temps, i would at least want a gauge to keep an eye on it. If the truck is hurting a little bit on hills..... time for more go-fast goodies!!:-laf

 

[JR2]

Get 4. 10's and run 285 tires..... you will be at about a 3. 73 If you don't like that then you could go back to stock tires and have 4. 10's again. .

 

[VHolloway]

I Have The 410 With The 285 Tires It Works For Us

But When We Had The Stock Size Tires When It Rained And You Would Make A Turn The Tires Would Spin

We Run 285/75/16 Bfg Mt D Rated

Next Set Will Be Bfg At E Rated

Thanks

And God Bless Us All