Moving a 740 with no rear subframe.

[maxitoman007]

My rear subframe has twisted and snapped in my 1987 Volvo 740. I was wondering if it would be okay to remove the subframe, as it is now hitting the driveshaft, and then drive the car a short distance into a garage. Is it safe to move the vehicle under its own power for a short distance without the rear subframe?

[Dan]

How far? up the driveway? You still have the trailing arms, I think a short distance at very low speed should be fine

[2manyturbos]

No. You can push it in. Without the sub frame you will not be able to apply any power whatsoever without having the rear axle rotate. It's physics, plain and simple.

[PCH]

I would be afraid to destroy the drive shaft/u-joints, lines, cables, etc.
The axle sits in the trailing arms that are designed to simply hold it in position- not prevent it from twisting inside the rubber bushings (called bearings I believe). If you absolutely must- then accelerate very very slowly, no uphills and throw it in neutral when you decelerate. But I wouldn't even want to try this.

[2manyturbos]

^^ You elaborated on what I said. OP, you could really tear things up trying to move the car without the other two links installed.

[Dan]

Originally Posted by 2manyturbos

No. You can push it in. Without the sub frame you will not be able to apply any power whatsoever without having the rear axle rotate. It's physics, plain and simple.

Yeah, true, forgot the subframe keeps the axle from twisting, good catch

[2manyturbos]

Originally Posted by Dan

Yeah, true, forgot the subframe keeps the axle from twisting, good catch

Had you owned a 240 you wouldn't have forgotten. The torque rod bushings in those go bad at about 150K. I picked up one from a transport driver that brought it up from an auction in California and we couldn't even drive it going easy on it. The drive shaft kept coming up to the floor with the slightest application of the gas. I can't imagine if they weren't in there at all.

[maxitoman007]

Sounds good. I will not be moving the vehicle without it.

[Dan]

Originally Posted by 2manyturbos

Had you owned a 240 you wouldn't have forgotten. The torque rod bushings in those go bad at about 150K. I picked up one from a transport driver that brought it up from an auction in California and we couldn't even drive it going easy on it. The drive shaft kept coming up to the floor with the slightest application of the gas. I can't imagine if they weren't in there at all.

Eh, I've owned at least a dozen, just never had one with bushings that bad , I was mentally picturing the rear end and just thinking of side to side and front and back, didn't get to torque reactions

[2manyturbos]

^^

I figured as much. Just stoking the 9>7>2 argument. Math never lies.

[Dirty Rick]

Just a thought regarding moving with broken torque links.

Even applying the brakes can cause the uncontrolled axle housing to rotate and this includes the E Brake.
This can cause damage to brake lines/hoses, cables, driveshaft, etc. (even fuel lines if things go really bad)

[2manyturbos]

^^ True. He should be fine using the brake pedal though. You are using all four brakes then. Using just the e-brake would be a really bad idea.

[c1800]

Originally Posted by 2manyturbos

^^ True. He should be fine using the brake pedal though. You are using all four brakes then. Using just the e-brake would be a really bad idea.

Why would using the brake pedal vs the e brake have any different effect on the rotation of the axle ?

[2manyturbos]

Originally Posted by c1800

Why would using the brake pedal vs the e brake have any different effect on the rotation of the axle ?

Using the brake pedal, all 4 disc brakes are going to stop the car. The axle won't be doing all the braking and should remain relatively centered. Just using the e-brake means the entire load is on the rear brakes. The axle housing is definitely going to rotate when the brake is applied.