Part Time 4WD Conversion Owners (1 Viewer)
- Thread starter TOY350
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Delta VS
Supporting Vendor
Did you also install different gears? Or just the spool?
Yes, I did install the marlin crawler low gear.
Delta VS
Supporting Vendor
I meant the high range gears, not low range. Are you talking about a whine in hi or low?
I only installed the low gear but hear a high pitch whine when in high gear.
RFB
97 FZJ80 LIFTED SC DUAL BATTERIES,37s
I just did exact same trucks not rolling yet, but ill let you know If I have whine from marlin, if thats what your asking.
I got a 1998 HDJ80 with a part time conversion (H151F transmission with part time HF2A part time T-case), I wanted ABS back so installed the Marks 4wd ABS relocation kit... still got ABS light On and Speedometer stop working (it was working perfectly before ABS relocation, also tested the VSS on another 80, it's good).
any advice?
any advice?
Bumping this thread back to life. Great reading.
SHELLBACK
SILVER Star
I have a marks part time 4wd kit still new in box! If anybody is interested or knows anybody who wants it please let me know! We didn't end up using it.
I did PT when i added crawler gear, high range underdrive and its been great for the past year. This is one of the better mods i have done so far.
I finally got the p/t kit installed along with lo/hi range gears and unfortunately am seeing worse mpg’s in the CA 3FE with 33s. I also have lunchbox locker in the rear. I have run 2 gas tanks through it mostly in town, and can make only 160 miles now, yikes. Best i ever got before any mods was 250 mi/tank and I’m pretty stock. Questions:
Break-in period for this mod?
Speedo ratio/reading get altered?
Pretty bummed. Have verified everything works and front is locked out (2wd). Ideas?
Other FYI results:
Tires often screech on takeoff(peel out)
With A/c on can overpower brakes in 1st gear
Easier in tight spaces/soft tighter steering
Limited felt performance if any in 2wd
Hubs look cool
Break-in period for this mod?
Speedo ratio/reading get altered?
Pretty bummed. Have verified everything works and front is locked out (2wd). Ideas?
Other FYI results:
Tires often screech on takeoff(peel out)
With A/c on can overpower brakes in 1st gear
Easier in tight spaces/soft tighter steering
Limited felt performance if any in 2wd
Hubs look cool
Did you do overdrive or underdrive high range gears?
Break-In period is 500 miles. Have you GPS calibrated your speedo using a converter?
The part-time conversion will not yield much fuel economy, some see some, some see none. But you should not see worse economy, particularly the numbers you are seeing. Is your t-case hot to the touch after driving 20-30 miles?
The high range is under drive. I didn’t know about gps speedo calibration but i will look into that. As far as hot t-case i will run it and report back. Thank you @cruiseroutfit
i have high range underdrive/ PT, 37s and a VB upgrade on my A440F and i avg about 250 ish on a full tank, and i am around 5800 lbs something is not adding up with yours 3FE
update: I ran it for about 3/4 of a tank last weekend on a highway trip (average 49mph, max 75). The mileage is only fractionally off, with odometer reading 1-3 mph below actual speed. During 41 miles, it measured 38. The MPGs went up considerably during my trip of only about 15 miles out of 140 miles in-town. This leads me to believe that the low gears are not happy. I do occasionally here a minor "clink" when it downshifts (4th to 3rd I think).
The T-case was very hot after first 25 miles (in 40 degree weather), but... I reached a half tank at around 130 miles (which equals more like 140 miles)! Highway miles were nearly double the mostly city miles I was turning out in the first 2 post-conversion tanks. i believe I have not seen this high of Highway mpgs, and this low of city mpgs before.
Also, on a side note (prior to my above trip) after using low and high 4wd in my back yard for 30 minutes (rescuing trailer and boat from mud) the following 2wd trip down my street yielded minor/light grinding noise for 2-3 seconds during an (automatic) up or down shift of the gears (10-25 mph range). Happened twice. After the 2nd time I stopped, placed in reverse, and went about 30 ft. No more noise, and have not heard since.
The T-case was very hot after first 25 miles (in 40 degree weather), but... I reached a half tank at around 130 miles (which equals more like 140 miles)! Highway miles were nearly double the mostly city miles I was turning out in the first 2 post-conversion tanks. i believe I have not seen this high of Highway mpgs, and this low of city mpgs before.
Also, on a side note (prior to my above trip) after using low and high 4wd in my back yard for 30 minutes (rescuing trailer and boat from mud) the following 2wd trip down my street yielded minor/light grinding noise for 2-3 seconds during an (automatic) up or down shift of the gears (10-25 mph range). Happened twice. After the 2nd time I stopped, placed in reverse, and went about 30 ft. No more noise, and have not heard since.
I’ve taken temp readings off my transfer case with an infrared Thermometer back when it was stock. 200*f plus was normal after some road driving. Seems illogical that under drive gears rendered worse mph around town where they actually help the engine accelerate and improved mph on the highway. One thing I don’t like about the under drive gears is the whining noise they make.
Well that is good to know that a hot T-case is not abnormal. I dont think water would have sizzled on mine but it was cooking pretty good. I wish my son didnt throw my Infrared Thermometer in the toilet, I used that thing for everything. My new gears do not whine, and it is slightly quieter when cruising. I wasn't aware the high range underdrive gears did anything in town... how do they help engine accelerate?
The 10% underdrive high range is the same idea as regearing on the 3rd. So basically if you have stock 4.10 gearing on the 3rd,, the 10% will give you close to 4.88 gearing etc. I am running 4.88 on my 3rd and add the 10% high range underdrive, i ended up with a 5.29 final gearing ratio to run my 37s.
copy that. I bought and researched the gears 4 years ago and didnt install them until recently I apologize for my ignorance. I was remembering about the gains on the highway (lower rpms) and thinking it was just effecting 4th gear and forgetting that my ratios changed across the board. 
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