[hugejp]

Heya,

Anyone possibly have a set of Marks 4wd 0.7 5th gear overdrive on the shelf?

I'm trying to establish the tooth count on the gears.

I'm chasing a set for my td42 & there is a bloke with a set for sale, but I'm not sure that they are legit Marks gears. Photo attached -

These show 41 - 20

Please if anyone can confirm the correct amount of teeth.

Cheers
J

 

[GutSquisher Media]

This don't workout the Marks kit states "Marks 4WD 5th Gear 0.74:1" and going by the pic on their web site the small gear has 21 teeth not 20 it would be best to ring them.

 

[hugejp]

Confirmation from Marks - 21/38 tooth count.

So now to figure out what exactly these 20/41 gears are?

 

[Trollbasher]

Cabstar trucks ran the same gearbox with a remote shifter top.
5th gear is way taller than the Patrol runs.
Probably out of a Cabstar or nissan civillian.
Crucial part is whether the shafts are the same spline and diameter.

 

[hugejp]

In a perfect world if these were to fit the Patrol main shaft & counter shaft, what do you think such a big reduction would drive like?

It's quite a big jump from the 1:1 4th, to a 0.66:1 5th

Any opinions?

 

[peterc3004]

I have thought about a taller 5th gear. That 34 percent jump would be patrol only and not suit me for towing. Would need more power than a std patrol me thinks to pull it.

 

[GQshayne]

I have used the Marks overdrive, and with the TD42 engine I do not consider it suitable matched with 4.11 diff gears. 4.3 or 4.6 would be a different story.

 

[hugejp]

GU td42ti - running 29psi, 12mm pump, 37" tyres, 4.6 gears - considering 5.18 gears.

 

[GQshayne]

GU td42ti - running 29psi, 12mm pump, 37" tyres, 4.6 gears - considering 5.18 gears.

Hmmmm......... I would have thought that with 37" tyres the 5th gear revs would be ok with 4.6 diff gears. If anything I would have guessed the revs would be too low.

I reckon you need 2000rpm or more in 5th gear, what do you have now?

 

[hugejp]

100 - 2450 - 37"
110 - 2700 - 37"
120 - 2900 - 37"
-------------------------
100 - 2600 - 35"
110 - 2850 - 35"
120 - 3100 - 35"

 

[GQshayne]

100 - 2450 - 37"
110 - 2700 - 37"
120 - 2900 - 37"
-------------------------
100 - 2600 - 35"
110 - 2850 - 35"
120 - 3100 - 35"

Yep, I am with you know. About 2100-2200 is a nice place to be. I reckon the overdrive would get you back to about 2100 from memory.