General Questions on GU Patrol mods 33s 35s gearing auto lockups etc

[Xtreme]

Hi Guys,

I am putting together these questions - although I know every subject has probably been covered a thousand times - because I am finding it a bit difficult to find the time to spend searching through the forum and hoping these questions can be answered (once again) in one place for me that is relevant to my build.

2000 ST GU patrol auto, 285k, dawes and needle valve, EGR, 3 inch exhaust with cat, Boost and EGT gauge, 33" BFG AT on std rims ROO systems chip. I bought this patrol last year with 245k on the clock and full service history to do a trip round OZ towing a 3T van (which we did - 9 months and 40K) The car did ok it returned 22L/100k not sure if that was good or not but it was very sluggish on hills - I drove to the EGT gauge not the speed limit and kept it under 400 deg C on the hills - on the flat it did not register on the temp gauge which starts at 300 deg C.

I was running 15 boost but have since dropped it to 12 pounds but notice that now I am not towing anything it is running a bit hotter so I am going to return the boost to 15 pound.

Questions:

1. Have now sold the van and will not be towing ( maybe a camper trailer in the future) and will now mod it to suit mild to hard 4wding. I would like to run 35's MT (leaving the 33 AT for road driving) and wanted to know what gearing is best for both the 35 and 33's. At the moment gearing is horrible for 33s. It either sits on 1500 RPM @ 100 with the overdrive on and feels like it is lagging, or on 2900 RPM @ 90-95 with the OD off and feels like it is revving to hard. I did read on one post the suggestion is to run 85% reduction for autos - is this gearing in the transfer case?
2. What difference between changing gearing in the transfer or the diffs?
3. Has anyone used the Wholesale Automatic Transmissions locked up kit? To give 100% engine breaking on decent? Any experience or opinions on this would be appreciated.

http://automatictransmission.com.au/...p?NewsId=42068

4. I would like to keep the build low and stable while being able to fit the 35's. Can I get away with a 2 inch lift and guard chop or 3 inch lift?
5. What offset should I have on the rims to clear 35 x 12.5?
6. Has anyone installed or had experience with the Automatic Transmissions upgraded valve body? The gear changes in mine feel very slow and sluggish and wondered if this would help eliminate it.

http://automatictransmission.com.au/...sp?NewsId=8169

Any info on these questions would be appreciated and I hope to get a bit of time to start up a build thread soon.

Thanks Guys.

[FNQGU]

Re the gearing - a reduction gear in the transfer case is only for low range. You might need to look at diff ratios.

Re the Wholesale Automatics manual lockup kit - I have it and like it. It is great for those times when at or just under highway speeds and the bloody auto wants to kick down all the time and hunt between lockup and 4th. I haven't tried it yet, but believe i can also program for lockup in 3rd and even 2nd, which might be great for beach work, if I ever did any.

Re the Nomad valve body - yep, that is great too. Very quick changes, although sometimes can be harsh. It is better again when driven hard.

I am now a convert to Auto and must admit I love being able to drive it like a manual when I feel the need. Having set it up like I now have it, I would not go back to manual.

Others will be better at advising you on tyres and diff ratios.

My 2c...

[Xtreme]

Ok thanks mate sounds like you have your set up sweet now. It all reads like it will do the things I want it to but did not want to spend money on things that are not going to really make much of a difference so if it does get rid of the sluggish changes I will do the valve upgrade - did you also get the converter upgrade at the same time?

The dropping in and out of lock up was exactly what mine was doing so I will get the lock up kit as well.

[FNQGU]

I did a whole transmission job, from upgraded friction plates to the torque converter, to the manual lockup kit and Compushift II. Cost a bomb but very happy with it.

[Xtreme]

Thanks for the feedback on the transmission. Anyone have any ideas for the gearing for 35's?

[Xtreme]

Ok from what I can find throughout the forums it would seem that I should run 4.6 diff centres for the 35's to bring gearing back close to standard with a little loss on top end speed. This was not stated whether or not it is the same for autos, of which I am guessing the diff ratios are the same just probably gearbox ratios are different?

I see that the 2.8 motors came out with this gearing std so can anyone tell me if a 4.6 centre from a 2.8 patrol would fit into the diff on my 2000 ZD30?