Torque Setting?

[Ooooner]

I am reassembling my front suspension and when I torqued the lower control arm bushings, it seemed to be extremely tight. When I read the factory manual, I thought this setting was for 40 ft. lbs. These bushings are the ones which have the inner metal and outer metal sleeves. I am using poly bushings. Did I read this right?
Thanks for any thoughts on this....

[jordan]

I believe the torque specification for those bolts are 18 ftlbs. All the manuals I have do not have very good or decisive torque specs. for the front suspension, and the description of what is being torqued is vague.

[namba209]

Roy, I know for sure I torqued the upper and lower control arm bolts, but I can't find the info in amy of my manuals. Maybe it was in the instruction sheet that came with the poly bushings from OGTS and I can't find that either.

[Ooooner]

Originally Posted by namba209 Roy, I know for sure I torqued the upper and lower control arm bolts, but I can't find the info in amy of my manuals. Maybe it was in the instruction sheet that came with the poly bushings from OGTS and I can't find that either.

Ron,
The poly bushings I got from OGTS didn't come with any torque settings in the bag. So I tried to use the 73 service manual for reference but like Jordan said, it is very vague. I saw a torque setting that was 18 ft. lbs. but it was for the brackets that hold the rack and pinion assembly to the suspension frame. I may try the 18 ft. lbs. but that seems a little on the loose side to me.

[guyopel]

Roy The torque for lower A-Arms to the cross member is
35 ft/lbs. Spring eyelet bolts are 18 ft/lbs. the lower control arm bolt that holds the bushings in is 40 ft/lbs.
HTH
John

[GTJIM]

None of the Manuals I have specify the torque for the Lower A-arm Bush bolts.

Lower clamp bolt for steering shaft ... 22 lb-ft (3.0 kg-m)
Upper clamp bolt ........................... 14 lb-ft (2.0 kg-m)
Cross member to frame bolts ........... 36 lb-ft (5.0 kg-m)
Crossmember to side panel bolts ...... 18 lb-ft (2.5 kg-m)
Caliper mounting bolts .................... 72 lb-ft (10 kg-m)
Upper ball joint attaching bolts ......... 22 lb-ft
Upper ball joint castellated nut ......... 29 lb-ft
Lower ball joint castellated nut ......... 45 lb-ft
Upper A-arm mounting shaft nut ....... 33lb-ft (with spring tension relieved)
Lower A-arm pivot bush retaining bolts ... (no value given)

[Ooooner]

Originally Posted by guyopel Roy The torque for lower A-Arms to the cross member is 35 ft/lbs. Spring eyelet bolts are 18 ft/lbs. the lower control arm bolt that holds the bushings in is 40 ft/lbs. HTH John

GTJim and John,
Thanks for the information. I used the 40 ft. lbs. and it is so tight that the pivot part that is in between the two bushings will hardly move. It just seems way too tight. Maybe it is supposed to be that way. I don't know.

[GTJIM]

It is the size (thread diameter!) of the bolt which determines the torque value - just have a look at the sizes of the bolts which do have torque values and use the value for a bolt of the same size as the Lower A-arm bush retaining bolts. That is the best advice I can give!

[jordan]

As bolts go the LCA bushing bolts are not that critical, They do not do much in holding extreme forces. As soon as the washer is snug against the inner sleeve It's purpose have been executed, you do not need to kill the bolt by tightening. All it has to do is stay snug and you're golden. 40ftlbs sounds very extreme for the size of the bolt in a threaded section, it is testing the bolt's elastic yield every fraction of a turn as it is a rotational and tension type situation and not just tension as if a nut were involved. I really wish some actual torque values existed for things like this.

[Ooooner]

Originally Posted by jordan As bolts go the LCA bushing bolts are not that critical, They do not do much in holding extreme forces. As soon as the washer is snug against the inner sleeve It's purpose have been executed, you do not need to kill the bolt by tightening. All it has to do is stay snug and you're golden. 40ftlbs sounds very extreme for the size of the bolt in a threaded section, it is testing the bolt's elastic yield every fraction of a turn as it is a rotational and tension type situation and not just tension as if a nut were involved. I really wish some actual torque values existed for things like this.

Jordan,
Of all the torque settings, this one is not given. I wrote to OGTS and to see what they say. I was on "Opel Chat" tonight and we all agreed that 40 ft. lbs. seemed to be too tight. So I am going to get 4 new grade 8 bolts and go with 25 ft. lbs. We'll see what happens... Thanks...

[namba209]

Roy, et.al., I forgot to add, from USAF training, hold the bolt head with a wrench and torque only the nut. That way, you eliminate any friction drag that may give incorrect torque values. One thing I have decided on, when I had the "bolt from hell', at least once a year, I'm gonna back off the nut on the UCA/LCA bolts and give them a 1/2 turn or a full turn, just to be sure they don't rust-weld on me again.

[jordan]

Ron, we are talking about the LCA bushing bolt that actually holds the bushings in, there is not a nut to it, just the threaded cast piece that the "bolts from hell" go into at a different location.

[namba209]

Jordan, you're right, I was referrinng to the UCA, the real long bolt that goes through a sleeve. That's the beasty that gave me fits.

[Ooooner]

OK guys, here is what I got back from OGTS this morning. I just copied it over to here:

The factory manual does say 40 ft. lbs. (1973 edition).
But 40 ft. lbs., is under stock original perfect conditions.

That doesn't apply to arms with 30 years of wear
and tear, possible rust, and aftermarket polyurethane
bushing replacements. All those can cause deformations
and affect friction, that will give you a false torque reading.
(We don't have new arms, bolts and GM rubber bushings anymore).

As preparation, I would clean the threads of the bolt
on a wire wheel or with a wire brush. Then I would
use a tap to clean out the threads of the arm's
shaft (within the inner washer). Then I would lightly
lube the threads of the bolt with loc-tite (or a similar
anti-seize/threadlocker) and tighten to where the bolt
is snug on the arm (but doesn't tear the poly bushing
on movement).

What this point is on your car, I don't have a specified
number for. But those are the considerations that could
go into your individual decision.

Opel GT Source