Towing: Which Gear??

[TFPRDO Junior Member Find all posts View Profile Close TFPRDO]

Hi all,
I have a 99 V6 manual, petrol and have just bought a camping trailer to do the Cape in later this year. Have been told that you should never tow in 5th gear as it can overheat and put too much pressure on the gearbox. Can anyone confirm this??
Look forward to your thoughts.

Cheers


Paul

[croozza Avid PP Poster! Find all posts View Profile Close croozza]

Depends on the weight your towing. Anything more than 1800kg then avoid 5th gear. But seeing as you only have a camper trailer you will be fine to use 5th gear.

[williade Avid PP Poster! Find all posts View Profile Close williade]

What croozza said, except I'd probably avoid 5th if the combined weight of the vehicle and the trailer are greater than the GVM of ~2700kg.

The owners manual does state not to use 5th (or 4th in auto) when towing anything at all.

[fishfinder Advanced Member Find all posts View Profile Close fishfinder]

I have done plenty of towing with a 1200kg camper and I only use 5th when on flat road,if I feel the car labouring at all then I will drop down to 4th just to be on the safe side.

[TFPRDO Junior Member Find all posts View Profile Close TFPRDO]

Thanks guy's. Much appreciated on your advise. Wanted to use 5th gear due to fuel economy but didn't want to jeopadise mechanical problems. Common sense comes into a lot though. Camper is only about 600kg's so should be safe to use on the flat stuff.
Cheers again.

[K & M McF Senior Member Find all posts View Profile Close K & M McF]

I use 5th all the time when towing my 2 tonne boat so long as it is flat. No problems in 12 years.

[croozza Avid PP Poster! Find all posts View Profile Close croozza]

What croozza said, except I'd probably avoid 5th if the combined weight of the vehicle and the trailer are greater than the GVM of ~2700kg.

The owners manual does state not to use 5th (or 4th in auto) when towing anything at all.

Thats me out then, my GVM of the vehicle alone is 2700kg....lol

[KZJ90 Member Find all posts View Profile Close KZJ90]

Always in 5th on flat and uphill too, as long as there is enough torque. 1600 kg/250 cm wide caravan trailer behind. So much rpms in 4th, 5th feels much better choice. No problems so far.
I have used RVS products in gearline, I think it may help the gearbox last longer. http://www.rvs-tec.com/English/index.htm

[t303 Senior Member Find all posts View Profile Close t303]

Guess I have to be the voice of dissent here ;-)
I would(do) avoid towing in fifth for the following reasons:
Fifth gear is the smallest cog in the gearbag and splined onto the mainshaft in this box, which is good, but this is an R series Toyo box; I think it's the same one that gets put behind Supras and sundry other cars. It is not the H? series that is put into some of the Cruisers, which I gather is a much stronger box. It probably won't self destruct tomorrow, but it must wear faster than running straight through the box in 4th. Would be interesting to connect my spare temp sensor to the gearbox.
Another thing I have noticed since I have been watching boost/EGT/coolant temp is that even with just a rooftop tent and a load in the back, when in 5th gear the engine often pegs out at 11psi with the EGT rising to high 600'sC on even a moderate incline, a good hill will result in my EGT alarm going continuously (700C pre turbo) and coolant temp rising up to +7C until I either back off, or shift back to 4th at which time the EGT will drop to below 600C with coolant following within seconds. Sure, you may need to drop back to 90kmh, but high EGT=more diesel being burnt and more heat going past the valves. Also remember that these low capacity diesels are designed to rev, unlike 4.2L sixes. You won't believe the rate that all the params rise until you see it for yourself, it sure surprised me!

[Brooksy_95 Lurker Find all posts View Profile Close Brooksy_95]

Wow that's great information. I'm new to this forum, but had noticed with my diesel that at times towing in 5th makes the car run hotter (also noticed this with a 2.8d 4runner previously) and simply dropping back into 4th with a bit less speed seems to overcome that then.

[croozza Avid PP Poster! Find all posts View Profile Close croozza]

Everyone seems to have forgotten that the original post was for a PETROL V6. There will be no problem towing in 5th gear for the manual or 4th gear if an auto.

If you have a diesel, then dont be lazy when towing, drop down a gear or two for hills. This is one of the reasons the diesels blow head gasgets, the exhaust temps get high and the heat on the exhaust side is much higher than the other side, that difference in temp warps the head and the gasket blows. Lucky it is not the Nissan 3.0ltr, you melt number 4 piston on them.