NP 203 gear change question

[drewmech]

Plan is to pull the NP208 transfer case and hook it up with a NP203/205 doubler. I know where to find the lower gears for both transfer cases but I was wanting to up the gear ratio in the HI range in an attempt to gain alittle bit better cruising speed at lower engine speeds when not on the trail or towing. Basically use the hi range of one of the transfer cases like an overdrive gear without the hassle of having to switch to a 700R4 tranny. Anyone ever heard of this or know some where I can look? Or am I just asking a dumb question?

 

[kennyw]

There are no gears in the high range of a transfer case. It is just a direct drive through the tcase with a 1:1 ratio (directly coupled shafts from input to output).

 

[drewmech]

Ok dumb question then. Thanks.

 

[Croatan_Kid]

Swapping in a 700R4 would be cheaper than doing a doubler. I say do both! Get the lower first gear of the 700 and the 4:1 low range of the doubler....or put a LoMax 3:1 low range in the 205 and get 6:1 low, low range.

 

[POOR WHITE BOY]

A 4l80e would give you a overdrive and is a very strong unit . I have a low max 205 case in one of my trucks . It has the dual stick - hnl and also fnr. Also upgraded front out put . Very nice case but it cost $2,300.00.

 

[kennyw]

Swapping in a 700R4 would be cheaper than doing a doubler. I say do both! Get the lower first gear of the 700 and the 4:1 low range of the doubler....or put a LoMax 3:1 low range in the 205 and get 6:1 low, low range.

Swapping a 700R4 into a wheeler is like putting 27" swampers on as an upgrade from your stock 31" tires.

 

[drewmech]

Yeah I'm not a fan of the 700R4. Always seem to pull them for the same reason: Won't shift out of second gear. As I understand it this is cause by a pump failure. The pump won't develop enough hydraulic pressure to move the transmission into 3rd and 4th. I maybe wrong this is just how I had it explained to me. Either way it does not have a very good reputation on the street or the dirt.

The other option I thought of threw further research was a twin stick set up on the NP205. Underdrive 4LO and custom overdrive gearset for 4HI use the second stick for control over the front and rear axles. Figured this set up would grant a broad range of gearing even without the NP203 mixed in. Not sure if this is possible just figured I would ask those who know more then me.

 

[Recovry4x4]

I've had really good luck with the 700 trannies.

 

[drewmech]

You must being doing something I'm not. 3 buddies had 700R4's in there trucks a stock 89 burban, a 78 C-10 street truck (not a stock tranny to the truck but a stock rebuild on the tranny with a cam'ed and carbed 350), and a 91 K-10 on 33's all replaced them in short order due to mechanical failure. All 3 trannies would shift from first to second just fine but would not shift into third or fourth. Reverse worked as advertised as well. After troubleshooting (change fluid, filter, leaks of any kinda, metal in the pan, etc...) we finally just tore them out and installed other trannies in their place. Sold the R4s off to a local transmission shop as cores. Only complaint I've ever had with a TH350 or TH400 is the lack of a 4th gear.

 

[Recovry4x4]

Perhaps because all mine were behind 6.2 diesels? Dunno. Have 200,000 on my 91 Burb with 6.2 700R4 and it works great. TV cable adjustment is paramount for tranny life! Putting together parts now for a 700 swap into my M1008.

 

[drewmech]

I don't know I come across people who swear by the 700R4 for street/strip and off road use. I come across people who absolutely hate it no matter where it is. Maybe I should give it a try. I just get a bit nervous about spending my hard earned money on a part with a checkered history.

 

[POOR WHITE BOY]

Put a 4l80e or a 4l85e in it and be done with it. I have used them all in my pull truck - the red and silver truck in my sig. The 700r4 can be built to handle the 1000hp going into it. Its the 60k pound sled that my truck is hooked to - that is where the turbo 350 and 700r4 are not strong. A turbo 400 , 4l80e .4l85e will hold up . You will need a stand alone computer or have it built to work without electronics. This will give you a good strong set up. The newer models even have 5 speeds:-d TCI OFFERS THEM WITH 6 SPEEDS - 3.1 1ST GEAR - MIGHT NOT NEED THE DOUBLER. I have a 1991 crew cab with a 4l80e -ex air force truck - makes a big difference with the overdrive .

 

[Recovry4x4]

Love to have that 91 CC there pwb. I was hoping for the 4L in this 91 burb but starting life as a half ton killed that! Did N AZ paint his truck yet?

 

[POOR WHITE BOY]

I have been in the hospital - have not been by his house -had some red primer on it monday. Yes, i to love my 91 cc. They are the best of the old body style in my eyes.

 

[Croatan_Kid]

I like the 700R4 and that's because I've built several of them for myself and others. Once you've torn one apart and built one, have an understanding of how they operate, and what you can do to improve their weaker points, you can appreciate what they are. Two of the best aftermarket parts they make for them are the constant pressure valve bodies and the 13 vane pump/rotor kits. Also, as mentioned, the TV cable adjustment can be associated with 95% of 700R4 failures even though it's probably the easiest part of setting one up.

Plenty of wheelers run 700R4s, again, the lower first gear attracts them. Stephen Watson, owner of Off Road Design, runs/ran a 700R4 in his Blazer and nobody can say that it didn't see some extreme wheelin

I'll agree, 4L80Es are great, but the cost of that computer really turns me away, but the biggest reason I chose the 700R4 is because it was going behind a 6.2


Oh...and puttin 27" Swamper on from some stock 31s might be an upgrade as most stock tires are only made for the highway Sure you'd lose some GC, but traction is nice too. (Just saying)