gearing/towing/torque???

[jx2mad]

It seems from what I have read here that 5th gear should NOT be used for towing. Is this because 5th gear is not strong enough, or is it because it places the motor outside its optimum torque revs below 80kph or what. My defender tdi seems to be over-reving in 4th gear at 80kph, so what is the answer other than crawl along in 4th at 60? Jim

[Disco_owner]

It seems from what I have read here that 5th gear should NOT be used for towing. Is this because 5th gear is not strong enough, or is it because it places the motor outside its optimum torque revs below 80kph or what. My defender tdi seems to be over-reving in 4th gear at 80kph, so what is the answer other than crawl along in 4th at 60? Jim

Jim;

you've pretty much answered your q's, 5th gear on the R380 isn't strong nuff for Towing . I recall JC saying that to someone on here.

[weeds]

i use 5th on the flat, drop it back to 4th on hills

i quite often sit on 80km/h in fourth = most days driving to work

[slug_burner]

Jim;

you've pretty much answered your q's, 5th gear on the R380 isn't strong nuff for Towing . I recall JC saying that to someone on here.

X2

I have also had my R380 rebuilt twice, once for main output shaft spline wear and the second time for input shaft and laygear disintegration. I consider this second failure to be associated with putting too much load onto the laygear when pushing fifth. The Gbox did not let go when towing but I did have a couple of sets of steel wheels in the back of the defender after attending a liquidation auction and crusing home on 110km/h. The vehicle had done a bit of towing a heavy boat before I owned it so the damage may have been done before I got the vehicle.

[PAT303]

The R380 is strong enough as long as you don't expect it to haul up hills.Use it properly and they are fine. Pat

[rovercare]

5th gear, isn't part of the main shaft cluster like the other 4, making it inherently weaker, towing in 5th is to be done wearily, like posted above, on flat and light loads are cool, but when it labours, time for 4th, the strongest gear in the bag

[Blknight.aus]

but its not a gear...

its just a coupling.....

unless its an auto....

[dmdigital]

I don't know what your problem is?

5th gear is great for towing ...


... but unless you're cruising on the open road, 6th gear is definitely not for towing







Oh, wait a minute, 6th That'd be where reverse is on the pre-07 Defenders

[tempestv8]

In the pre 07 Defenders, 4th gear is (as per the norm) the 1:1 ratio, with drive going through the gearbox in a straight line, hence the strongest gear for accelerating uphill during towing. Fifth gear, being the overdrive, is OK for cruising on flat roads with steady throttle but not recommended for towing. It's much cheaper to use more fuel and rev the motor harder than it is to repair the gearbox... coz that's both time and money down the track.

However with the post 07 Defenders, i.e. PUMA, I'm no longer sure whether 4th gear is the 1:1 ratio, which I suspect it still is, i.e. both 5th and 6th gears are overdrives. I did read the factory training manuals which the service techs were given during their product training, but that was a couple of years ago now, and my memory isn't the best....

[jddisco200tdi]

In a Puma defender 5th gear is 1:1.

I think the rules are simple, as soon as there is any undue strain change down however many gears required. This can be before the engine is appearing to labour.

My brother had a 4.2 rangie with an LT77. Never seemed to labour but thats not to say you weren't putting a lot of torque load on the bearings in the gearbox if you were in too higher gear.

Regards

John D - Defender 110 2.4