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Does anyone know what Volvo was addressing in changing the length of the torque rods? Vibrations? U-joint failures? Loading issues?
Just curious.
DS
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The old 240/260 greenbook for rear wheel suspension states:
Three different rod lengths are available
1 - 402mm - standard
2 - 397mm - 5mm shorter
3 - 392mm - 10mm shorter
Rods 2 and 3 are used to lessen vibration on takeoff.
further the greenbook saith not, no mention of part numbers or what year they started/stopped offering alternate rods.
John
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Verily! Yeah, though I scramble on the driveway in the shadow of suspension, I fear no Volvo, for the Greenbook....etc etc. Thanks for the sourcing, much appreciated.
402mm is 1273621-1, 397mm is 1329615-7 and 392mm is 1229836-0--I've found that much. No way of knowing if those are current numbers on a Sunday. I'm trying to find something that might confirm that all three lengths were available first in the old, hourglass-bushing, small eye style and then later in the large eye style.
DS
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402 mm is standard. There is a 5mm shorter 397 mm and 10 mm shorter 392 mm. the shorter rods would be to elminate any vibration during takeoff. It all has to do with the angle of the driveshaft. Probably used more when turbo models were around.
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I THOUGHT the only adjustable Torque rods were aftermarket. They were made for people Lowering their suspension. The adjustable rods were used to keep the Pumpkin straight as the lowered the spring height. Any angle would work the 'U' joints a bit more. Volvo has a very Straight angled drivetrain. The 'U' joints last a very long time on the 200's.
Do you have adjustable Rods on your car?
--
'75 Jeep CJ5 345Hp ChevyPwrd, two motorcycles, '85 Pickup: The '89 Volvo is the newest vehicle I own. it wasn't Volvos safety , it was Longevity that sold me http://home.lyse.net/brox/TonyPage4.html
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Hey Tony. No, no adjustables on this car, although I've got them in my lowered wagon. But yes, only the aftermarket are adjustable in that respect.
I'm a little confused at this point. I pulled down the Jags That Run V-8 conversion manual, and sure 'nuf, they talk a little about the rods. I just measured a '77 and it's about 16 1/8 center to center or almost 410mm. I just measured the ones in my wagon (91) too, they are 402mm. JTR lists 402, 397 and 392.
Lots of conflicting info so far on lengths, that's for sure.
DS
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Almost would have to be vibrations due to the orientation of the pumpkin.... but I've never heard of different lengths on stock 240's.
-Ryan
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Athens, Ohio
1987 245 DL 324k, Dog-hauler
1990 245 DL 142k M47, E-codes, GT Sways/Braces, Dracos, A-cam
1990 744GLE 189K 16-valve
1991 745 GL 304k
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Yep yep, I agree. Shortening the rods drops the nose of the diff which is usually done to address shudder on takeoff. I wonder if that is what they were up to. If I knew the length of the third rod, and what type of ends it had, I could make an assumption. I've been browsing some parts sites that handle Volvo replacement rods. They show a single rod for all years (Parts Geek for example).
DS
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I don't recall there being different rods for sedans vs. wagons... or 6-cyl vs. 4-cyl... or gas vs. diesel. Only the old vs. newer style.
If I get some time later, maybe I'll poke around in VADIS to see what story the part numbers might tell.
Was there ever a factory change in ride height?.... perhaps a GT/turbo or Group A sort of thing? Hmmm....
-Ryan
--
Athens, Ohio
1987 245 DL 324k, Dog-hauler
1990 245 DL 142k M47, E-codes, GT Sways/Braces, Dracos, A-cam
1990 744GLE 189K 16-valve
1991 745 GL 304k
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I don't think it has anything to do with sedan or wagon, just angle. As to ride height, there sure is a lot of argument across the web about whether or not the GTs had different springs. My take on that is that all the springs were the same (excepting wagon rears). Tuning was done with the bars and shocks. I don't know about the Homologation Specials though, seems likely they'd have something special.
Ride height certainly does affect pinion angle. I wonder if these were offered as a means of coping with the "standard" loads different people carried in their vehicles. Looking at the drive shaft in the 77, it is almost perfectly straight from the trans right to the pinion. I'll bet the angle is almost zero. Makes one wonder what happens when you put 400 lbs of passengers and luggage in it. I'm tempted to put shorter rods in it when I do the bushings.
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David -
I don't know the answer to your question, but a few more details? Changeover year, length extended or shortened by x amount, etc.
Regards,
Zach
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I'm not certain of the years. Early cars, pre-81, seem to have the longest rods with the small eyes. I'm not certain if 81 is the changeover year to the large eyes or not, I don't think so. I seem to recall finding small eyes in an 82 once. The larger eyes are definitely shorter rods and I know that they start at least as early as '83. Apparently there are three lengths, just to make things more confusing.
DS
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VADIS lists at least 4 different part numbers for a 1982 Volvo 244 but, unfortunately, does not tell us what the differences are. I know one of them is the earlier "hourglass" style but they all remain a bit of a mystery as to the differences in lengths...
--
Dale
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Thanks Dale and Yama. I have no doubt that when I pull the rods out of the 77, the bushings are going to be torn, allowing for the longer c to c measurement I'm getting.
DS
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