Perentie winch

[optimax90]

Is there an adjustment to the clutch on Thomas pto winch. I've used it a few times an it seems to slip a bit too easy. Had a look today can't see adjuster anywhere. My series 3 / bamford winch has adjustment on pto , am I missing something?

[weeds]

from memory our greaser tweaked the GMV 6x6 winch clutch's.......not 100% certain though

at times I had to engage the transfer case to assist when in sand or mud/wet conditions (wheels would spin and unload the clutch enough fo rit to winch in).....keep in mind my GMV was usually over its GVM >5500kg

how heavy and what conditions? winching uphill? weight?

I guess all things wear out at some stage

refresh my memory is the clutch in the drive assembly or along the drive shaft?

[optimax90]

I'm not sure where the clutch is. When it slips it sounds like its in he winch itself. Could be wrong, very loud when it slips. It struggled to pull me out of deep sand uphill, a lot of strain on it , maybe it's how they are? Series 3 type seems to take a lot more.

[isuzutoo-eh]

The clutch is in the drive assembly. Cue Bearman with the right info...

[Blknight.aus]

The pto slip clutch (torque limiter) is a ball and spring detent setup on the rear of the Tcase extension housing that mounts to the bottom of the Tcase and houses the drive gears and chain.

Drive is transmitted to the chain from the main input gear down to the outer gear on the PTO shaft. It has 16(from memory) detent holes in it 12 of these contain springs and balls. the rear cap is bolted on and transmits drive to the center shaft via the interference of the balls in their drive sockets and the dentent dishes in the shaft cap.

When an overload condition exists the balls climb up the incline of the detent dishes in against spring pressure allowing controlled slip in the drive mechanism.


you can increase or decrease the pressure by adding or subtracting detent balls and springs or replacing the springs with stronger or weaker springs.

Increasing the torque limit on the mechanism is NOT reccomended as the slip feature is provided to prevent damage to the worm gear that provides the final drive and direction change in the winch.

[weeds]

I'm not sure where the clutch is. When it slips it sounds like its in he winch itself. Could be wrong, very loud when it slips. It struggled to pull me out of deep sand uphill, a lot of strain on it , maybe it's how they are? Series 3 type seems to take a lot more.

Being on sand I reckon low range would have help the winch

[optimax90]

Thanks for the input. I'll give it another try tomorrow, I'll also start using a winch block/ pulley, make it easier.

[Blknight.aus]

dont forget to take into account the number of turns on the drum.

bottom layer is good for 3636kg, second 3024kg 2589kg third and 2263kg on the top layer.

if the rope is bunching as you winch in you loose pull at the equivalent distances of the layers.

[Bearman]

Is there an adjustment to the clutch on Thomas pto winch. I've used it a few times an it seems to slip a bit too easy. Had a look today can't see adjuster anywhere. My series 3 / bamford winch has adjustment on pto , am I missing something?

Quite possible your winch may have seen a fair bit of use in service and the detent springs are weak and/or the torque limiter drive plate that the balls engage may be grooved or furrowed from slipping. If you still think that it is slipping too easily you could replace the springs/balls and inspect the plate at the same time. The part number for the springs is AYG3492 and MYH3170 for the balls (12 of each). Get the balls from a bearing shop (8 mm diameter), bit cheaper there. The drive plate is AYG3518 but hopefully you wont need to replace that. If it is grooved where the balls have been slipping you will probably be able to recover it with a light surface machining. Adding another 4 springs/balls will increase the torque and make it harder to slip but you then have to be careful you don't damage the winch itself under extreme load. They are a very strong winch but you can damage anything if you try hard enough!! Wherever possible use a snatch block to halve the load on everything and engage low range and 1st gear as well..

[303gunner]

The pto slip clutch (torque limiter) is a ball and spring detent setup on the rear of the Tcase extension housing that mounts to the bottom of the Tcase and houses the drive gears and chain.

Drive is transmitted to the chain from the main input gear down to the outer gear on the PTO shaft. It has 16(from memory) detent holes in it 12 of these contain springs and balls. the rear cap is bolted on and transmits drive to the center shaft via the interference of the balls in their drive sockets and the dentent dishes in the shaft cap.

When an overload condition exists the balls climb up the incline of the detent dishes in against spring pressure allowing controlled slip in the drive mechanism.

you can increase or decrease the pressure by adding or subtracting detent balls and springs or replacing the springs with stronger or weaker springs.

Increasing the torque limit on the mechanism is NOT reccomended as the slip feature is provided to prevent damage to the worm gear that provides the final drive and direction change in the winch.
There is a spacer in the torque limiting clutch, shown as part No6 on the diagram below. This spacer comes in 3 sizes: 5.5mm, 6.0mm and 6.5mm. Reducing the thickness increases the pressure on the balls, and the torque that the coupling will release at. The spacer could be replaced with a thinner part, or reduced by filing or linishing if you're a bit handy. As Blknight has said, you don't want to increase the torque limit too much as this is designed to be the "fuse" protecting the PTO driveline.