Straight cut LT230 gear question

[buzz66]

Just got my truck back after having the 30% straight cut crawler gears fitted to my overhauled Lt230 transfer case.

I realise that straight cut gears make plenty of whine.

In low range and doing around 20 KMH. I was surprised how quiet it actually is, when power is applied that is. However when you take the foot off the throttle the overun noise is very loud, like about 5 times louder.
Turns people heads in the Robina car park I tell ya.

High range its very quiet.

Is it normal to have much louder gear whine on the overun?

Does anyone have these gears manufactured from MR? Just wondering how good Mal's hand over was when MR took over the manufacture of these gear sets.

[Bush65]

I had the 30% reduction gears from Mal.

They whined a lot during drive. It has been a good while since I used it and don't recall how much different it was on over-run.

[Lotz-A-Landies]

The design of straight cut gears means that they will always be more noisy than a helical gear-set. The question is Is it acceptable?

The other issue is that they may take a little time to bed-in and remove all the imperfections in the back faces of the teeth. After all it's now the same as a series transfer case and they always had a lot of noise in low ratio.

[justinc]

Agree with Diana , it is basically the same noises as driving in reverse gear, which is also straight cut. Under load they are reasonably quiet, but on the overrun and coasting they can be quite noisy..

JC

[mox]

Have a project in progress (for my 300Tdi Defender) that will give 1.27:1 high range and 4.21:1 low through transfer box instead of standard 1.41 high and 3.32 low. . Had a gear cut to replace the standard 26 tooth input one that drives the 41 tooth middle gear of the cluster in an LT230 with 1.003:1 high range. It has 22 teeth and drives the 44 tooth high range gear on the cluster.

Have to assemble box properly then instal it in vehicle.
Has anyone heard of this modification, which would only be practicable starting with a 1.003 high range LT230 being attempted before?

[buzz66]

Thanks everyone for the replies. Looks like the louder overun noise is normal. Thanks for the tip about the old series landies, It sounds just like that only a little louder

[cewilson]

Have a project in progress (for my 300Tdi Defender) that will give 1.27:1 high range and 4.21:1 low through transfer box instead of standard 1.41 high and 3.32 low. . Had a gear cut to replace the standard 26 tooth input one that drives the 41 tooth middle gear of the cluster in an LT230 with 1.003:1 high range. It has 22 teeth and drives the 44 tooth high range gear on the cluster.

Have to assemble box properly then instal it in vehicle.
Has anyone heard of this modification, which would only be practicable starting with a 1.003 high range LT230 being attempted before?

I changed my high range from Defender to Disco, which made it a lot better on road.

Low range was then changed to the Maxi-Drive straight cut gears - again it made it a lot better.


Problem with the set-up, especially the high range changes, is that bigger tyres will not work without changing the diff ratios.

Cheers
Chris

[mox]

Re my modified early Rangie LT230 described above with slightly faster high range and slower low than standard Defender one: I have no intention of running larger than standard tyres. Just 7.50 or 235/85x16 on 6.5 inch wolf rims that I have several spares of. Also most of my driving is in flat rural areas. Seems 5th high a bit faster would be more of an improvement than a similar small increase in high first and reverse may be a disadvantage . Slower first and reverse than standard in low would also be better.

Have already received an offer from someone to buy box that is currently in vehicle with standard 1.41:1 high. I gather wanted for Discovery with big wheels that is used a fair bit in the city where fast takeoffs at lights are preferred.

[Albert]

[QUOTE=cewilson;1060138]I changed my high range from Defender to Disco, which made it a lot better on road.

Low range was then changed to the Maxi-Drive straight cut gears - again it made it a lot better.


Problem with the set-up, especially the high range changes, is that bigger tyres will not work without changing the diff ratios.

I have problems with to high a ratio with LT85 behind 4BD1. When you say it made it better with the disco high range, did it raise your revs? do you know what the ratio is?
I would like to do what you have but would hate to end up with something worse.