D22 ST-R Braked Towing Mass

[Dion]

D22/D21 shared chassis topic, bit hard to put it in the right spot so I hope here is okay.

I have to talk GVMs and rear axle capacities with the engineer who signs off on my five link rear, and while I'm there I may as well push the point of GCM as well.

So, the D22 ST-R ZD30 has a braked towing mass of 3000kg.

The Gen 1 D22 4x4 with the QD32 has a braked towing mass of 1500kg.

Meanwhile all 4x4 dual cab D21s have a braked towing mass of 1000kg.


As far as I know, the chassis are close to identical across that whole range... same front/rear diffs, similar braking package (ABS in the D22 Gen 2?, plus rear load sensing valve), same rear suspension, very similar front suspension...

The primary differences between all those units besides the superficial, interior, panels, etc, is the engine and transmission package.

So what causes the 300% increase in towing capacity? Is it Nissan stating what the transmission will cope with and what the engine can pull? Does the 300% originate purely from the hairdryer on the ZD30? Or is it safety? It's hard to know what internal reinforcing changes there are inside the chassis rails between models.

Anybody aware of what gives the D22 its massive GCM?

 

[Krankin]

and the '22 ST-R 2.5 crtd is back down a bit at 2800k Btm.

Me tinks there is as much hocus pocus in those figure's as there is in the manufacturer advertised Hp figures.

 

[joshy]

zd30 dual cab is 2.8t, zd30 single cab is 3t.
Cant help with any more then that? you sure the brake discs are the same, drum sizes the same?

 

[Peter ST_R]

I reckon Nissan realised that 3000Kg towing capacity would sell more vehicles so they said it could do it. There is no way in hell I would try to tow 3000Kg behind mine as I think it would be unsafe and end up damaging the vehicle.

 

[tweak'e]

3 ton is easy enough to tow. as long as you have suitable trailer and is loaded correctly.

probably the biggest difference between d21-d22 would be the brakes and tires.
but what you can tow with it is only limited by your local laws.

 

[Dion]

Joshy,

I pulled my figures from a towing mass guide made by the caravanning association of Australia or something. I'd believe you before I believed them, so 2800kg it is.

tweak'e,

The tyres are the same size, load rating and braking performance could be a different story, the D22 may have shipped with higher rated tyres but I can't see where the ~300% improvement is in the tyres?

The brakes, well they're not a different size by much if they are. I'll dig up figures and check. They're still disc front, drum rear, some D21s had LSVs as far as I can tell, still rear loop/front loop hydraulic with vacuum booster...



I know for sure the TD27 can't haul 3000kg. I know the overdrive gear would shit itself at the thought. Might this be the reason? Not safety, just a working limit?

 

[tweak'e]

i thought D21 had far skinnier tires and 15" rims.

 

[Dion]

i thought D21 had far skinnier tires and 15" rims.

16". Weren't you just the other day looking at a new D22 running 205s?

Anyway, I just then asked a friend who is in the industry and most of the difference is almost certainly the fact that the engines and gearboxes of the D21 are incapable, so Nissan has reduced the braked towing mass to avoid warranty claims.

The rear brake is unchanged. The front brake package changed with the introduction of the ZD30 engine from model CL28VD to CL33VD, incorporating an increase in cylinder bore diameter from 42.8 to 46.4mm, a rotor diameter increase from 277 to 283mm. The pad is roughly the same size, but changed shape to accommodate the rotor change.

 

[tweak'e]

d22 are 16", i thought the early d21 where 15" ?? not many manufactures would have had 16" on that size vechile. i'll try to ask the neighbour down the road what they have on theirs.

but yes it could well be a mechanical limit rather than a safety limit. i think ford (and others) did the same with the falcon so people didn't stress the driveline (weak gearbox).

nice find on the disk sizes.

 

[joshy]

id say the driveline, in particular the gearbox would be the reason then as youve said.

 

[Dion]

d22 are 16", i thought the early d21 where 15" ?? not many manufactures would have had 16" on that size vechile. i'll try to ask the neighbour down the road what they have on theirs.

but yes it could well be a mechanical limit rather than a safety limit. i think ford (and others) did the same with the falcon so people didn't stress the driveline (weak gearbox).

nice find on the disk sizes.

Cheers.

The ugly stock wheels that came on my 88 were 16". I went to brand new 15" wheels.

Alright, well, glad I've worked that out. Not sure what the engineer is going to think of that.

 

[Dave]

STR D22 dual cabs are rated for 2800kg towing capacity, DX's are rated at 3000kg.

I have had 3.5t or there abouts behind my D22 and it did it fine.

The car trailer was 2t and a EH of the back, a EH would 1.5t I would think.

Dave.

 

[Dion]

The car trailer was 2t

Heavy car trailer!

 

[joshy]

thats what i was thinking, sure it wasnt just rated to 2t dave?

 

[Dave]

I have a pic somewhere of a EH on it, on the draw bar it had the tare weight and GCM.

Tare weight said 2T and the trailer was rated for like 2.8T.

There is a pic on my members section, I have never seen a trailer so over engineered.

Dave.

 

[Dave]

I have had the tray of the ute loaded up with dirt and box trailer with dirt in it up to the sides and they felt like less weight then that trailer alone, I haven't seen the guy who owns it for a while but Ill try and get some info.

Dave.

 

[tweak'e]

the trailer won't weight two ton unless someone filled it with lead. tandem are usually around 500kg -700kg