Chassis extending or shortening

[AmyBee78]

Looking for a company to complete a chassis extension or reduction in the south. We are based in Oxfordshire.
Can anyone recommend any companies that offer this service?

Chassis and wheelbase extending or shortening

Thanks

 

[Mick Annick]

Looking for a company to complete a chassis extension or reduction in the south. We are based in Oxfordshire.
Can anyone recommend any companies that offer this service?

Chassis and wheelbase extending or shortening

Thanks

Truck, car, trailer, what make?

 

[8ob]

Looking for a company to complete a chassis extension or reduction in the south. We are based in Oxfordshire.
Can anyone recommend any companies that offer this service?

Chassis and wheelbase extending or shortening

Thanks

Rules and regs have changed on this, can’t remember the date but it was a few years ago now. They have to be signed off and inspected by the truck manufacturer, not many are prepared to sign off other companies work so its pretty much a main dealer only mod.

Bob

 

[AmyBee78]

Truck, car, trailer, what make?

Truck, Iveco eurocharger.
Have now spoken to Iveco and they have a recommended company they use for all modifications in Bristol so going direct. Think it’s the safest option considering the other post from 8ob below.
Thanks

 

[AmyBee78]

Rules and regs have changed on this, can’t remember the date but it was a few years ago now. They have to be signed off and inspected by the truck manufacturer, not many are prepared to sign off other companies work so its pretty much a main dealer only mod.

Bob

Thanks Bob,
Going direct with Iveco as they have a preferred company in Bristol. Thank you for the advice.

 

[nickk]

Rules and regs have changed on this, can’t remember the date but it was a few years ago now. They have to be signed off and inspected by the truck manufacturer, not many are prepared to sign off other companies work so its pretty much a main dealer only mod.

Bob

Rules and regs have changed on this, can’t remember the date but it was a few years ago now. They have to be signed off and inspected by the truck manufacturer, not many are prepared to sign off other companies work so its pretty much a main dealer only mod.

Bob

When did this change Bob? I did a land rover extension some years ago

 

[8ob]

When did this change Bob? I did a land rover extension some years ago

It’s more to do with the info/plate changes/needed when submitting the vtg10, some of which needs to come from the manufacturer . That’s the sticking point.
Always wondered if the lengthening/shortening of chassis had an effect Ackerman, most of the ones I have come across eat front tyres.

Bob

 

[Agrismith]

It’s more to do with the info/plate changes/needed when submitting the vtg10, some of which needs to come from the manufacturer . That’s the sticking point.
Always wondered if the lengthening/shortening of chassis had an effect Ackerman, most of the ones I have come across eat front tyres.

Bob

I thought lengthening was the problem not shortening.
Some lorries come with the chassis pre drilled for different wheelbases so is only a case of moving the spring hangers forwards and chopping off the excess. No structural work required.

 

[bricol]

.
Always wondered if the lengthening/shortening of chassis had an effect Ackerman, most of the ones I have come across eat front tyres.

Bob

In theory, and I guess practically, yes. Hence the tyre wear. The whole geometry of the front end should be configured to the wheelbase - change the wheelbase and it all goes wrong.

 

[minimutly]

In theory, and I guess practically, yes. Hence the tyre wear. The whole geometry of the front end should be configured to the wheelbase - change the wheelbase and it all goes wrong.

well considering ackerman is only needed for tight turns, mostly at walking speed I would expect this to be incorrect. anything with an extended chassis would have not enough, and anything shortened too much. Either way they both would still have some.
Race cars have little or no Ackerman, and rarely need it, except maybe for tracks like Monaco. And the car park...

 

[sickpup]

Would this work require an IVA test afterwards?

 

[rtcosic]

I always thought that the lines through the steering arms should intersect at the centre of the rear axle, so I checked the definitive source these days:

Wikipedia

So my memory hadn't failed me. That would indicate the steering arm geometry should be changed to match the changed wheelbase.

 

[colnerov]

Would this work require an IVA test afterwards?

Yes.

 

[8ob]

Would this work require an IVA test afterwards?

With cars or vans I think it does, with commercials it comes under notifiable changes hence the need to fill in the vtg10.
VTG10

Bob

 

[8ob]

well considering ackerman is only needed for tight turns, mostly at walking speed I would expect this to be incorrect. anything with an extended chassis would have not enough, and anything shortened too much. Either way they both would still have some.
Race cars have little or no Ackerman, and rarely need it, except maybe for tracks like Monaco. And the car park...

Race cars corner so hard the inside wheel is virtually unloaded which negates the need for Ackerman, a trucks front axle is a different story, geometry needs to be spot on. Quite a lot of horse boxes are based on stretched artic units, big engines and cheap make them a horse box manufacturers go to, its in these that I have witnessed this front tyre scrubbing.

Bob

 

[Trevorleach]

I always thought that the lines through the steering arms should intersect at the centre of the rear axle, so I checked the definitive source these days:

Wikipedia

So my memory hadn't failed me. That would indicate the steering arm geometry should be changed to match the changed wheelbase.

That is interesting.

Your link comes up as a toolstation woodscrew?

 

[colnerov]

That is interesting.

Your link comes up as a toolstation woodscrew?

Fat finger syndrome.

 

[pedrobedro]

That is interesting.

Your link comes up as a toolstation woodscrew?

Comes up with a torx head concrete screw on mine.

 

[rtcosic]

That's because that was the last link I had posted on another thread.

Less interestingly this is the one I meant:

Ackermann steering geometry - Wikipedia

en.wikipedia.org

 

[tom2207]

I lengthened a tractor into a long rigid to have a super low loader body mounted onto it two months ago , and had no issues at all with it , but then again recovery is in a class of its own for most things , Ive done a few now and have never had steering issues and have never messed with alignment or arm geometry , then again the time spent doing low speed full lock turns would be very very low compared to man many motorway miles.