towing with a 607 HDI auto

dieselnutjob · Unread post by **dieselnutjob** » 30 Mar 2010, 15:52

Does anyone have any experience / advice for towing with these cars?
My current tow car is a Peugeot 806 HDI manual, and that's a great tow car. I am wondering what the implications are of towing with the 607. I recently picked up a brand new Bosal removable hitch for it.
Engine:2.2 litre 16V HDI
Transmission: ZF 4HP20 with "tipronic" manual override option
Year: early 2001, actually built Dec 2000
The caravan: 22 year old Adria, 800kg empty probably over 1000kg with my stuff in it.
According to the owners manual I'm not supposed to tow anything with mine. It's okay with the diesel manual, and it's okay with the V6 petrol auto which I think is also 4HP20, but the combination of diesel and auto seems to be a problem.
When I called Peugeot UK they said that their records don't go back as far as 2001 but for the later years they say I can tow 1600kg.
My main concern is that I don't want to destroy the transmission. The car is heavier than the 806 and has bigger brakes so no problem there.
The manual page is here:-

Unread post by **CitroJim** » 30 Mar 2010, 16:25

The '20 really is a massively over-engineered 'box so why the warning about towing on one variant I don't know for sure. The '20 used in the V6 is different to the HDI version which I found to my cost using a HDI 'box as a spares donor for a V6. It's lower geared overall and the TC has a different stall speed* about 300 rpm higher than the V6 version.

I'd say, in sympathetic hands, you'd be fine towing so long as you are sensible and keep an eye on coolant temperature (and thus ATF temperature). The higher stall speed of the diesel TC may cause, if abused, a much higher rise in ATF temperature than is good and one thing the '20 does not like is overheated ATF. Remember that the car manufacturers rate things very much with the worst possible treatment and abuse in mind.

If any of the clutches/brakes slip due to overload the 'box will instantly fail to 3rd emergency mode and flash the sport and snow lights. Similarly, if the ATF gets too warm the same will happen as the ECU monitors ATF temperature.

When the towing gets heavy, I'd be tempted to keep the 'box in a lower gear to keep the engine revving fairly high to keep the TC spinning fast, freely and as close as possible to it's coupling speed (that's the speed at which there is only a very small amount of slip and torque multiplication and thus least power dissipation in the TC).

Most of the time the TC will be locked up but I'd not rely on it as the TC lockup clutch is a friction component and can fail catastrophically if overloaded. It could well be overloaded if the engine is allowed to labour at low speeds The clutch will be working hard to keep the TC locked with little help from the TC itself and much heat will be generated. If the lock-up clutch fails it fills the oil pump and filter with debris and results in a large repair bill...

Drive like a petrol when towing and you'll be fine.

I used to tow a lot back when the kids were younger and we had a touring van. I've never towed using an automatic though so all this is theory. My weapon of choice was always a Xantia 1.9TD. My V6 arrived well after we bid a fond farewell to the caravan. Even with the TD I always obeyed the 85% rule and found in that vehicle it was better to drive it more like a petrol engine. It ran cooler for one thing. I used to ignore 5th gear completely so towing with a '20 I'd be tempted to keep the selector in 3 and not let it see top at all. Another advantage of towing in third is that both drive clutches are engaged simultaneously and all brakes are released so any risk of clutch slippage is lessened. This is why the 'box fails to third in case of problems. It's the easiest gear to engage...

I think I'd give the 'box a fluid change before towing and make sure the
cooling system is tip-top.

One thing to watch on the 607 is the towbar noseweight rating. I see it's not quoted in the spec. sheet. I've known way in the past some seemingly potentially excellent towcars being totally unsuited because they could not take a great deal of noseweight. On a big van these days they can now run upwards of 70 or so Kgs and to not run the right noseweight is both dangerous (affects stability) and is an offence. This may be what is behind the warning that this car is not suitable for towing.

On the legal front, if the manufacturer says the car is not suitable, what are the implications of being stopped by the boys in blue when towing with it. Is an offence being committed?

* Stall speed is the maximum speed the engine will rev on full power with the transmission locked. A rough demo of it can be had by pulling the handbrake on very firmly, stamping on the footbrake, placing yourself well away from obstructions, selecting D and flooring the accelerator with all brakes hard on.

The speed the tacho reads after a couple of seconds of this is the torque convertor stall speed and is normally not that far above fast idle. Basically, all the engine power is being dissipated in the TC and as a result the fluid gets very, very hot very very quickly. Do a stall test only for seconds at a time. Too long and it can burst the TC apart. It's scary as you can feel the car wanting to launch like a dragster...

dieselnutjob · Unread post by **dieselnutjob** » 30 Mar 2010, 16:49

I think that the police have to go by what's on the VIN plate and not what's in the user manual, which they might not even have access to.

I think that the VIN plate only has Gross Vehicle Weight and Gross Train Weight so I would consider those as my legal maximum figures.

To be honest I think that your average copper would struggle to even find the VIN plate on a 607 as they are quite hidden.

Anyway there is no way that I'll be exceeding either GVW or GTW to I'm not worried about that.

I might have to be a bit more careful about nose weight though. The 806 is an eight seater and has very little overhang at the back coupled with springs tough enough for 8 adults. With only 5 of us I think that a bit of nose weight really isn't a problem. The suspension is basically Peugeot Expert van suspension.

The 607 doesn't have the same advantages in that respect.

cachaciero · Unread post by **cachaciero** » 13 Apr 2010, 21:06

I don't know if this is relevant but I had occasion to find out what the max towing weight for a 2.2 C5 with 4HP20 was, much to my surprise it was quite a bit lower for the auto than the manual 1000kg max as I remember. I came to the not unsurprising conclusion that the auto box could not handle the extra power probably related to time and heat.

cachaciero

wheeler · Unread post by **wheeler** » 14 Apr 2010, 00:05

Is that not maybe because the autobox is quite a bit heavier than the manual version therefore the GTW being reduced to account for this ? Just a guess though.

cachaciero · Unread post by **cachaciero** » 18 Apr 2010, 10:01

wheeler wrote:Is that not maybe because the autobox is quite a bit heavier than the manual version therefore the GTW being reduced to account for this ? Just a guess though.

The weight difference is only about 30Kgs doesn't really explain the difference between 1500Kg towing weight manual and 1020KG Auto

My guess is that the cooling is inadequate for the higher loads.

cachaciero