are adjustable torque rods (240) really effective? 2007-2020 bump

[apollo's 940]

1991 240 wagon

in process of poly'ing all bushings with sport springs and adjustable panhard rod.

I can see the point of the panhard rod (left to right misalignment) BUT . . .

how does the torque rods work?

if you lower the car with sport springs. . . the axle moves up closer to the body and what else?

does it move back further?

the torque rods should not be affected because the trailings arms are still equidistant with the axle, correct? it will simply shift up (meaning the axle) .

so what is the point in adjusting anything ?

reason is . . I want to keep my stock torque rods and just plug in polys.

andrew

[Captain Bondo]

The interaction of the links is difficult (at least for me) to explain, but I'll try.

You are correct to suggest that when you lower the car, the axle moves forwards/backwards (I actually can't remember which way- I just set up my rear suspension, but I have a different diff now so I am hesitant to comment on which way a stock one moves). Suffice it to say that it does.

Why? becuase the torque rods are shorter than the trailing arms, so if you lower the axle, the angles of all of the links change. The angle of the torque rods changes more becuase they are shorter, which means at the end where they bolt to the diff, they are no longer aligned with where the trailing arms attach to the diff, so the diff is no longer "straight up and down.

This has 2 side effects:

1)as I sais it moves the diff either forward or backward (tires no longer center in the wheelwells)

2)it changes the pinion angle, or the angle of the diff's input flange where the driveshaft bolts up. This all has an effect on how the diff rects when torque is applied to it.

Adjustable torque rods allow you to compensate for the fact the the angle of the torque rods and the angle of the trailing arms have not changed equal amounts.

I have no idea if that made any sense.

Anyways it is a good thing to correct this geometry change, but not critical.

[towerymt]

They are useful for adjusting pinion angle of the axle when lowering the car. They are also useful for moving the wheel/tire forward or backward to gain tire clearance for tall or wide tires. I don't think you really need them. I've never used them and I've had my car quite low at times and never had driveline vibrations. When changing to a one piece driveshaft, it seems that the pinion angle is more critical and fine tuning is necessary.

[apollo's 940]

thanks for the explanations guys. but I still dont get it.

I crawled under the car. stared and stared and stared and all of a sudden it clicked.

adjustbale torque rods DO NOT contribute anything.

I will stick with stock plus poly.

andrew

[gsellstr]

As towery mentioned, with a 1-piece driveline it's a little more critical to have the pinion angle correct to avoid vibrations. I've got them on the 140 which has a 1-pc. driveline. Without the angle was just a bit too far off giving me a nice bit of vibration. Dialed the angle back in with the adjustables. As for the stock setup, 90% of the cars are here wouldn't need to mess with anything, but there are a few that MIGHT benefit from them. Kinda depends on the use of the car, how everything's setup, and that kinda thing.

[JohnMc]

Mostly pinion angle. I have a 1-pc driveshaft in my lowered 240 and I didn't need to mess with the pinion angle. I'm using the IPd spring, Bilsteing HD's. I did put 1" spacers under the rear for a tiny bit more clearance, and also to give the car a more aesthetic rake (always looked drooped down a little too far in the rear with the IPD springs F & R).

When I was measuring for the new driveshaft I got measurements from the end of the T5 case to the axle flange at full droop, ride height, and full compression. It really *barely* changes length.

[BDKR]

I bought them primarily to help with thrust angle. However, since it seems I'm going in the direction of 1 bit driveshaft, they just may be of help there.

The nice thing is that they made a huge difference in removing the slop that my worn bushings in the OE rods were providing. If you don't want the adjustability, at least replace the bushings in the rear.

[Mueller]

Originally Posted by apollo's 940

thanks for the explanations guys. but I still dont get it.

I crawled under the car. stared and stared and stared and all of a sudden it clicked.

adjustbale torque rods DO NOT contribute anything.

I will stick with stock plus poly.

andrew

if they don't do anything, why did I have to adjust mine yesterday when I lowered my car even more????

I guess I was dreaming that the wheels where not centered in the wheel well before adjusting...the further you lower a car, the longer the wheel base gets (with the type of suspension on a 240)

[Jeh]

Originally Posted by apollo's 940

thanks for the explanations guys. but I still dont get it.

I crawled under the car. stared and stared and stared and all of a sudden it clicked.

adjustbale torque rods DO NOT contribute anything.

I will stick with stock plus poly.

andrew

I have to disagree on that one. After I lowered my sedan using just the IPD springs (so it was lowered aprox an inch and not 2 or 3 via a spring hacking) they were needed to eliminate a mean vibration on take off (I have an auto and a 2 pc shaft). As it stands right
if I drive with 1 passenger and a light load in the truck its fine but if I add 2 people in the back seat or fill the trunk it comes back.

If you are going to a 1 pc shaft or a manual I cant say but I cant see how it wouldnt matter.

BTW how much cheaper is it just to get the bushings? and with the agrivation of changing them out is it cost/time effective?

[stylngle2003]

Originally Posted by Jeh

I have to disagree on that one. After I lowered my sedan using just the IPD springs (so it was lowered aprox an inch and not 2 or 3 via a spring hacking) they were needed to eliminate a mean vibration on take off (I have an auto and a 2 pc shaft). As it stands right
if I drive with 1 passenger and a light load in the truck its fine but if I add 2 people in the back seat or fill the trunk it comes back.

If you are going to a 1 pc shaft or a manual I cant say but I cant see how it wouldnt matter.

BTW how much cheaper is it just to get the bushings? and with the agrivation of changing them out is it cost/time effective?

you should consider doing the center support/bearing then, if your engine and trans mounts are known good

[JohnLane]

If you are making some real YANK you will tear up the stock torque rods. They get longer when you are being a savage.
I tore those up, double skinned around the ends (welded it up nice) and tore those up.
I've got Aurora rod ends in place of the torque rods. Fully adjustable. Works dandy and was the end of the rear toe change under (big) load.

[Jeh]

Originally Posted by stylngle2003

you should consider doing the center support/bearing then, if your engine and trans mounts are known good

That was all done prior to the turbo and lowering just due to age. It took quite a bit of playing to get it right though I would have to measure stock vs adjusted length to know exactly by how much. I would have paid extra to have adjustment without removing the rod.
That can be a pain.

[linuxman51]

mm the adjustable rods on my 740 serve a purpose, but hey, whatever floats your boat.

[2fast242gt]

Originally Posted by apollo's 940

thanks for the explanations guys. but I still dont get it.

I crawled under the car. stared and stared and stared and all of a sudden it clicked.

adjustbale torque rods DO NOT contribute anything.

I will stick with stock plus poly.

andrew

NOT true at all, without adjustable torq rods i could not run my 8" wide rims and be 3" lower than stock

[Mueller]

I'm not sure how much stronger the IPD bars are over the stock units, but just a quick look between the 2 you can tell the stock one will fail way sooner.....

for me, getting a brand new adjustable part with the bushings already installed was a easy choice...I could have built some nice units like Mr. Lanes, however overkill for my application when you factor in the time to source the parts and make them....

[sergitin34]

I am about to change the length of my IPD adjustable torque rods in order to align my pinion angle to the best possible number (keeping it as it should be), but then also trying to bring the wheels more centered in the wheel well. They moved to the rear and passenger side when the car was lowered.

I would like to ask if anyone here has the IPD sport spring (lowered) setup and has tried their 25mm wheel spacers in the back without rolling the fenders? I was assured by one of their sales staff there would be no need to roll fenders if done right, meaning getting all the adjustable rods and play with them... but now that I am into it I am a little bit skeptical about it.

Anyhow:

Long story short installed shorter sport springs and Koni shocks adjustable torque rods, new bushing at trail arms, adjustable Panhard rod and 25mm rear wheel spacers, still can not find a way to keep the wheels to not rub in the rear "lower tip" of the fenders (both but more drivers now that I moved the rear end towards the driver's side)by adjusting the Panhard rod to center the system, still rubbing in both fenders depending on weight load, etc. So I am trying to correct the pinion angle to see if the rubbing can get better without having to roll the fenders. Still, I run into a problem, I disconnected the front bolt of my torque rod, lengthened it by 1cm or so, and can not for the love of me bring the holes back to alignment in order to put the bolt back in... tried jacking up the front of the differential but the whole rear end goes up, no twisting as I wanted in order to make the holes align.

Any advice? IPD instructions only provide info in regards to how to install them in the same length as the stock ones, not a word on how to change their length. I called them but it's a holiday and not back until the next business day.

It's minus 20 outside in the garage and I am having a really bad time!
Merry Christmas

[Lankku]

Rubbing depends on your wheels and tires. I'd cut the fender lip where needed. That's also what the manual for original 20mm spacers says. Just dont cut the spot welds out or you have to do some new welds.

Loosen the axle bushing bolts on the trailing arms. The big bushes are preventing the movement.

[apachechef]

Originally Posted by sergitin34

I am about to change the length of my IPD adjustable torque rods in order to align my pinion angle to the best possible number (keeping it as it should be), but then also trying to bring the wheels more centered in the wheel well. They moved to the rear and passenger side when the car was lowered.

I would like to ask if anyone here has the IPD sport spring (lowered) setup and has tried their 25mm wheel spacers in the back without rolling the fenders? I was assured by one of their sales staff there would be no need to roll fenders if done right, meaning getting all the adjustable rods and play with them... but now that I am into it I am a little bit skeptical about it.

Anyhow:

Long story short installed shorter sport springs and Koni shocks adjustable torque rods, new bushing at trail arms, adjustable Panhard rod and 25mm rear wheel spacers, still can not find a way to keep the wheels to not rub in the rear "lower tip" of the fenders (both but more drivers now that I moved the rear end towards the driver's side)by adjusting the Panhard rod to center the system, still rubbing in both fenders depending on weight load, etc. So I am trying to correct the pinion angle to see if the rubbing can get better without having to roll the fenders. Still, I run into a problem, I disconnected the front bolt of my torque rod, lengthened it by 1cm or so, and can not for the love of me bring the holes back to alignment in order to put the bolt back in... tried jacking up the front of the differential but the whole rear end goes up, no twisting as I wanted in order to make the holes align.

Any advice? IPD instructions only provide info in regards to how to install them in the same length as the stock ones, not a word on how to change their length. I called them but it's a holiday and not back until the next business day.

It's minus 20 outside in the garage and I am having a really bad time!
Merry Christmas

ratchet straps can help align stuff

[242Bleek]

If you lower a 240 in the rear and you are flush or sticking out a bit with your tires the rubbing is horrible because of the semi egg shaped rear wheel well. I have this problem with gta wheels on my 245. Can't go any thinner on spacers and lip is rolled flat. It looks as if shorter torque rods would help gain clearance on the lip and center the wheel in the hole. Has anyone been able to remedy this with adjustable torque rods alone?

[KwikBrik245]

Adjustable torque rods are not pointless, as stated above. I would recommend against the poly torque rod bushings however. Grab yourself a set of Kaplhenke Racing Adjustable torque rods. I run the dual rod end set, but they also offer a hybrid rod that has a rubber bushing on one end and a rod end on the other. With this setup you can still get some of the factory absorption of the rubber, while increasing your suspension articulation (better traction and handling). The full poly rods will increase the binding of your suspension and won't allow the car to handle bumps and depressions in the road, causing oversteer. Check out

These are what I am running on both my 245 daily and my LS powered 744. Obviously a different model for 740s but they are the same general design.
https://www.bneshop.com/collections/...le-torque-rods

Here are those sweet Hybrid rods I mentioned.
https://www.bneshop.com/collections/...le-torque-rods

Not to knock IPD's products, but sometimes I want more than 1 flavor.


https://www.bneshop.com/collections/...le-torque-rods

[KwikBrik245]

Face Palm.....

I should've seen how old this is first lol

[blkaplan]

Originally Posted by KwikBrik245

Face Palm.....

I should've seen how old this is first lol

I'm sure it will help someone who is searching.

[KwikBrik245]

Originally Posted by blkaplan

I'm sure it will help someone who is searching.

Thank you for the sweet parts catalog! keep making 'em and I'll keep giving you the plug.

[sergitin34]

OK here is my take on is with some numbers for those who take my same route.

Bite the bullet and bought the adjustable Panhard rod and moved the car by 1/2 an inch towards the passenger side.

This is easier said than done, since I had no helper and needed to have acting forces to move it while I was down there trying to pierce the bolt in place, needed to make a jig with 2x4s and a Volvo scissor jack. Once finally done centering the car, it then would rub in both wheels wells.

Got to wor on the torque rods in order to try to see if this would help, but no luck either, the torque rods are linked to a bracket on top of the differential axle, and by the angle at the pinion these rods needed to be longer hence moving the wheels further back (where it was actually rubbing)... that discovery sucked for my enthusiasm. Anyway, here I will give you some numbers on how my angles changed just as an example for the future.

The Volvo stock driveshaft is split one, so I am still not completely sure what angles I need matching at this point to make this whole thing act as a CVJ, so I just went by the rule of thumbs saying you need about 2 degrees for pinion angle and the differential sloping slightly up in the rear so when the wheels hit the asphalt the counteracting forces will correct this angle closer as possible to cero. Of course, suspension action will make this change, but it will still remain in the happy numbers for everything to have a more efficient force transmission and less wear.

So from my first measurement, I was at 3.6 degrees @ pinion angle with the slope of the differential up @ the rear and about 0.6 degrees at the previous angle in the middle of the driveshaft with both segments of the driveshaft sloping down to the rear (the transmission output shaft was also slopping down, just so you know) I went 4 full turns (360 degrees) lengthening the torque rods and ended up then way too high in the diff nose ( can't remember exactly but by around the same amount than before just in the opposite direction) then I went to the blackboard and made some calculations that sent me in the direction of backing up 3 full turns and leave it at only one full turn longer than stock. After doing this I came up with 1.9 degrees with the differential sloping up in the rear and down in the "nose" the middle angle decreased to 0.4 degrees between the two segments of the driveshaft. This brings me very close to what I've read is the standard for a happy pinion angle. Making the holes align to get the bolts in this time was also a challenge and I did well too with the small scissor jack in different points where I could make the distances shorter or longer by an mm or two (the nose of the tranny or one specific wheel axle for example).

Just considering the fact that the best way to measure these angles is with the car in the floor and the car been so low reaching the shaft and the places to make an accurate measurement is quite difficult for those with just a garage and jacks and stands. I had to do this about 4 times! I was very glad when reached the right number for sure!


Any of this did not fix the rubbing, but that I already knew so I went and bought myself a fender roller from Eastwood for about 150USD after shipping and got to it, needless to say, this also proved to be a challenge (the rubber mud flaps bolt all snapped: 2 each side) and now I am having a hard time doing this for several reasons) the rolling also was challenging for a novice with this tool and even using a heat gun since we are in under 20 celsius here the heat might not be enough and paint cracking was happening, anyway, the wheels rubbing is gone now after the fenders are rolled only in their rear third segment where the rubbing was happening when the car bobbed deep in the suspension, but I have not yet put the mud flaps with their plastic trim yet and I hope these are not in the way otherwise I will have to go grinder on them and f@k it. Also, I mean to fill up the rolled lip with Bondo just so it does not collect all the salty slush from winter roads in there and makes the rust grow easier... just an idea.

My final conclusion is, if you lowered your car by the same amount of the IPD lowering (sports kit) are running Virgo or some 15" wheels with standard size tires and made it all tight with bushing work DO NOT PUT the 25mm wheel spacers in it will drag you through a lot of work to make this work alright, I would rather put that money toward the adjustable torque and Panhard rods to get things straight and safe the fender rolling nightmare and plus work still to be defined as I write these lines.

Thanks for reading.

[sergitin34]

Originally Posted by 242Bleek

If you lower a 240 in the rear and you are flush or sticking out a bit with your tires the rubbing is horrible because of the semi egg-shaped rear wheel well. I have this problem with gta wheels on my 245. Can't go any thinner on spacers and lip is rolled flat. It looks as if shorter torque rods would help gain clearance on the lip and center the wheel in the hole. Has anyone been able to remedy this with adjustable torque rods alone?

Shortening the torque rods might bring the wheels more towards the center but would also bring the pinion angle out of specs and a lot of problems can come from that, I imagine, with timings, etc at the rear wheel, not worth it. I ended up rolling my fenders and the rubbing was gone (25mm spacers and Virgos 15" rims with regular all-season tires on.)
good luck