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Need help diagnosing pop in freshly rebuilt front end 71RR

Posted By: Steve88

Need help diagnosing pop in freshly rebuilt front end 71RR - 08/11/15 04:20 AM

I have a 71RR that I just completed a full restoration on and it has an annoying pop in the front end. The pop mostly occurs on left turns and seems worse if there is a bump during the left turn. The pop seems to be coming from the driver's side. Everything is new in the front end. It has a Bob's Profab tubular K member, Firm Feel stage 2 steering box, Flaming river tilt steering column, Firm Feel quick ratio steering arms, Moog balljoints and bushings and all new steering linkage parts. I torqued everything in accordance with the service manual. I greased everything on install then after I noticed the pop so everything should be well lubricated. Any ideas what I may have missed or what I should check? Thanks for the help!
Posted By: TJP

Re: Need help diagnosing pop in freshly rebuilt front end 71RR - 08/11/15 04:23 AM

Double check all fasteners, bolt's etc..
Reading your post makes me question a shock bolt , DUNNO twocents
Posted By: RapidRobert

Re: Need help diagnosing pop in freshly rebuilt front end 71RR - 08/11/15 06:13 AM

Quote:
Double check all fasteners, bolt's etc..
that'd be my start. was the suspension loaded (at ride height when the bushings etc were finally tightened. As you know something is loose/moving when under stress
Posted By: 440whiteboy

Re: Need help diagnosing pop in freshly rebuilt front end 71RR - 08/12/15 01:46 AM

also look at your castle nut under tie rod or linkage arm?

I thought I had mine tight enough, finding it was way loose after.

just a thought - twocents
Posted By: flypaper

Re: Need help diagnosing pop in freshly rebuilt front end 71RR - 08/12/15 03:03 AM

go grab a buddy and jack up the front end of the car
and take the weight off the front suspension.
then have him move around the tire up and down with a bar and side to side
as hard as he can and while he is doing that, look for exessive slop or play in the front suspension or steering linkage.
alot of times the problem will be easy to spot.

Posted By: JonC

Re: Need help diagnosing pop in freshly rebuilt front end 71RR - 08/12/15 03:27 AM

Did you grease the torsion bar ends?
Posted By: Steve88

Re: Need help diagnosing pop in freshly rebuilt front end 71RR - 08/12/15 03:54 AM

Originally Posted By JonC
Did you grease the torsion bar ends?


Thanks everyone for the replies!

I am not sure that I greased the torsion bar ends. What parts of the torsion bars need to be greased? Thanks
Posted By: RapidRobert

Re: Need help diagnosing pop in freshly rebuilt front end 71RR - 08/12/15 04:57 AM

the front/rear hex ends
Posted By: Steve88

Re: Need help diagnosing pop in freshly rebuilt front end 71RR - 08/12/15 05:03 AM

Originally Posted By RapidRobert
the front/rear hex ends


Is it possible to get them properly greased without removing the torsion bars?
Posted By: RapidRobert

Re: Need help diagnosing pop in freshly rebuilt front end 71RR - 08/12/15 05:19 AM

no cuz they fit into the matching hex recesses pretty tight. EDIT If you do undo em be sure to measure the ride height on each side before so you can get it back to that exact height so as to not alter your alignment specs
Posted By: Adam71Charger

Re: Need help diagnosing pop in freshly rebuilt front end 71RR - 08/12/15 06:18 AM

I had a rattle in the front end every time I went over a bump. Thought for sure it was shocks or exhaust hitting oil pan. Drove me crazy cause I couldn't find anything wrong with shocks, exhaust or suspension. Turns out the joint that connects the steering shaft to the intermediate shaft was worn and the intermediate shafts was bouncing around.
Posted By: Steve88

Re: Need help diagnosing pop in freshly rebuilt front end 71RR - 08/13/15 08:32 PM

Yesterday I removed all the cotter keys and made sure everything was tight in the steering linkage. I snugged up the shock bolts and strut rods also but the pop is still there. I took the car for a drive and I was able to get the front end to pop even when going straight by loading and unloading the suspension so it does seem that it may be the torsion bars. I lightly lubed them when installing them but likely did not lubricate them well enough. I will pull the torsion bars this weekend and grease them up and see if that takes care of the pop. Thanks for the help.
Posted By: RapidRobert

Re: Need help diagnosing pop in freshly rebuilt front end 71RR - 08/14/15 04:33 AM

You might shoot some WD40 in the hexes just to see if it quiets em, likely would not last forever but that'd confirm that it is the tbars as it'd be better than tearing em down/greasing & then them not being it but there is a good chance it is them but I'd sure give it a shot. EDIT if you do undo em dont forget to duplicate the ride height exactly so you dont mess up your alignment
Posted By: Steve88

Re: Need help diagnosing pop in freshly rebuilt front end 71RR - 08/15/15 06:35 AM

I pulled the torsion bars and greased them last night but the popping noise is still there. I had a buddy come over today and turn the steering wheel so I could observe the steering linkage in action but I did not see anything out of the ordinary. I watched the steering shaft and steering box while he turned the steering wheel and I did notice the steering box input shaft moved in and out as it was rotated back in forth. The link to the video below shows the input shaft movement. The back and forth movement shown in the video is the slack in the steering box which is almost a 1/2 turn of the wheel before the pitman arm moves either direction. What is your opinion on the input shaft movement? Thanks

https://youtu.be/VUug7GxpSlI



Posted By: RapidRobert

Re: Need help diagnosing pop in freshly rebuilt front end 71RR - 08/15/15 07:35 AM

Quote:
What is your opinion on the input shaft movement?
I think we've ID'd the problem.
Posted By: Adam71Charger

Re: Need help diagnosing pop in freshly rebuilt front end 71RR - 08/15/15 05:08 PM

Glad you found it. And even though it may have been unnecessary now, you'll be glad that you got grease on those torsion bars in the long run
Posted By: Adam71Charger

Re: Need help diagnosing pop in freshly rebuilt front end 71RR - 08/15/15 05:09 PM

That want exactly my problem so I can't comment on that end play maybe someone else here can
Posted By: TJP

Re: Need help diagnosing pop in freshly rebuilt front end 71RR - 08/15/15 06:28 PM

Repeat the test with the wheels on the ground and the motor running as the hydraulic pressure may eliminate the end play. IF not time for a steering box. twocents
Posted By: Steve88

Re: Need help diagnosing pop in freshly rebuilt front end 71RR - 08/15/15 06:48 PM

Originally Posted By TJP
Repeat the test with the wheels on the ground and the motor running as the hydraulic pressure may eliminate the end play. IF not time for a steering box. twocents


That's a good idea, I will try that this afternoon. I was reluctant to think it was the steering box since it is new with only about 50 miles on it.
Posted By: AARCONV

Re: Need help diagnosing pop in freshly rebuilt front end 71RR - 08/15/15 07:01 PM

Check for cracks around where the k frame mounts to
Posted By: Steve88

Re: Need help diagnosing pop in freshly rebuilt front end 71RR - 08/15/15 07:29 PM

Originally Posted By AARCONV
Check for cracks around where the k frame mounts to


I will double check the K member mounts but the car does has a Bob's Profab K member that I recently installed so hopefully they will be ok.
Posted By: Steve88

Re: Need help diagnosing pop in freshly rebuilt front end 71RR - 08/15/15 08:23 PM

Originally Posted By TJP
Repeat the test with the wheels on the ground and the motor running as the hydraulic pressure may eliminate the end play. IF not time for a steering box. twocents


I tried the same test with the engine running and end the play is definitely less with the hydraulic power applied. Could I get someone with a power steering box to try the same test without thier car running to see if they get similar results from the steering box input shaft? It would be just moving the steering wheel back and forth a little without thier car running and observing the input shaft to the steering box. Thanks
Posted By: captaindodge

Re: Need help diagnosing pop in freshly rebuilt front end 71RR - 08/15/15 09:53 PM

The worm shaft should move in and out. That is what tips the spool valve fore and aft to turn left or right. Look at factory service manual.
Posted By: Adam71Charger

Re: Need help diagnosing pop in freshly rebuilt front end 71RR - 08/16/15 04:03 PM

Try grabbing the intermediate closer to where it meets the steering shaft. pull up down side to side see if there is slop or play
Posted By: TC@HP2

Re: Need help diagnosing pop in freshly rebuilt front end 71RR - 08/16/15 10:03 PM

Originally Posted By Steve88

the car does has a Bob's Profab K member that I recently installed so hopefully they will be ok.


Did you contact Bob's to see if they have any feedback on their systems doing this? Might be a commonly overlooked item.
Posted By: ruderunner

Re: Need help diagnosing pop in freshly rebuilt front end 71RR - 08/16/15 11:02 PM

Look closely at any parts that are bolted together, you're looking for shiny spots or chipped paint that indicates a part shifting around. You may need brighyt lights and a magnifying glass.
Posted By: Spaceman Spiff

Re: Need help diagnosing pop in freshly rebuilt front end 71RR - 08/16/15 11:34 PM

I see you have a lot of aftermarket front end parts, but state you torqued everything according to the service manual.
perhaps some/all of these parts have different toque values than stock, and something isn't tight enough, or to tight, causing binding?
Posted By: 71GTX471

Re: Need help diagnosing pop in freshly rebuilt front end 71RR - 08/17/15 01:31 AM

Retorque the aftermarket K frame.Find an auto tech with a set of chassis ears & go noise hunting.
Posted By: GomangoCuda

Re: Need help diagnosing pop in freshly rebuilt front end 71RR - 08/17/15 04:44 AM

Please correct me if I am wrong but the Bobsprofab k members that I have seen have r&p steering, coil over shocks and are intended for light weight race cars. Perhaps you have an Altercation k member instead.
Posted By: Steve88

Re: Need help diagnosing pop in freshly rebuilt front end 71RR - 08/17/15 02:50 PM

Originally Posted By GomangoCuda
Please correct me if I am wrong but the Bobsprofab k members that I have seen have r&p steering, coil over shocks and are intended for light weight race cars. Perhaps you have an Altercation k member instead.


I think Bob's Profab makes a couple different K members or at least did in the past. This one is few years old but takes all of the stock stuff except for a stock style swaybar.

I went out last night and double checked everything and made sure that everything is tight. I drove the car in front of my shop some and I did noticed that it is really more of a series of pops rather than just one pop. Going straight everything seems good then a very slight turn to the left I get 2-3 pops right together and same when turning back straight. It does seem to be worse if I turn while backing up. At this point I am open to any idea but I am fairly confident that its not anything being loose because I have checked and double checked all the fastners a couple of times. I can get an occasional pop out of it in my shop but its hard to duplicate the problem when not driving. With the the front wheels off the ground there is no issues at all. With the tires on the ground I get a pop occasionaly with the engine running or not. One I start drving it pops each time I turn and is easily duplicated but of course it is hard to see what is going on while drving.
Posted By: RapidRobert

Re: Need help diagnosing pop in freshly rebuilt front end 71RR - 08/17/15 05:07 PM

Any possibility the tbars ain't square? (as in horizontle) with that being an aftermarket setup. When it went together did the bars slide in with what appeared to be a good fit?
Posted By: GomangoCuda

Re: Need help diagnosing pop in freshly rebuilt front end 71RR - 08/17/15 06:18 PM

Quote:
It does seem to be worse if I turn while backing up.
Strut bar bushings? Are they urethane? If so they can creek and pop, lube them. Check strut bar mounting points on k frame and control arms for cracks.
Posted By: Steve88

Re: Need help diagnosing pop in freshly rebuilt front end 71RR - 08/17/15 08:21 PM

Originally Posted By GomangoCuda
Quote:
It does seem to be worse if I turn while backing up.
Strut bar bushings? Are they urethane? If so they can creek and pop, lube them. Check strut bar mounting points on k frame and control arms for cracks.


The torsion bars seemed to go in ok. Once I got control arms clocked where they needed to be the bars slid right.

I have been wondering if there is an issue with the strut rods. I used the stock strut rods with the Moog 7026 bushings. Is there a way I could have installed them incorrectly causing the lower control arm to get in bind? I probably should have went with adjustable strut rods since everything is aftermarket and that would have allowed for some adjustability.
Posted By: Steve88

Re: Need help diagnosing pop in freshly rebuilt front end 71RR - 08/18/15 02:39 AM

Well I think I got my problem figured out. 71GTX471 got it right above. After all the work I did on the moving parts trying to figure out the problem it ended up being the K frame bolts! I think I checked every bolt and fastener in the front end of my car except the K frame and then fixed the problem with a 5 minute retorque of the K frame. Thanks to everyone that offered up suggestions I really appreciate it.
Posted By: 71GTX471

Re: Need help diagnosing pop in freshly rebuilt front end 71RR - 08/18/15 02:53 AM

Glade to be of some help,when I worked for Mercedes I would encounter very similar noise complaints & many times it would be the sub frame mounting bolts.
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