Go Back   The Ford Barn > General Discussion > Model A (1928-31)

Sponsored Links (Register now to hide all advertisements)

Reply
 
Thread Tools Display Modes
Old 09-06-2020, 06:33 PM   #1
Mad Mac
Senior Member
 
Join Date: Mar 2013
Location: New Zealand
Posts: 308
Default Wandering

I have a "wandering" problem with my 29 RPU. When cruising along it tends to wander slightly to one side and after correcting, it wanders off to the other side, so I am more or less permanently correcting it. The problem is not serious, just annoying especially on longer trips. I have established that there is no play at all in the 7-tooth steering box (checked in the vice with a dial guage) so the play must be either in the king pins, drag link balls or tie rod.

My question: What is the easiest way to diagnose the cause of the problem without dismantling the whole front end? I have had the wheel alignment checked by a professional who says the alignment and toe-in is OK. So what do I check next? Hope someone can help with this.
Mac
Mad Mac is offline   Reply With Quote
Old 09-06-2020, 07:18 PM   #2
Jacksonlll
Senior Member
 
Jacksonlll's Avatar
 
Join Date: Jul 2012
Location: Michigan-- Member of Oakleaf of MARC
Posts: 1,489
Send a message via ICQ to Jacksonlll
Default Re: Wandering

Inflate your tires to 50 psi and try it.
The other thing you can try is to put a friends tires and wheels on the rear and try it. Easy to do.
Jacksonlll is offline   Reply With Quote
Sponsored Links (Register now to hide all advertisements)
Old 09-06-2020, 07:58 PM   #3
Jim/GA
Senior Member
 
Jim/GA's Avatar
 
Join Date: May 2010
Location: Young Harris, GA
Posts: 1,612
Default Re: Wandering

Mac-
Check your toe-in. Shoot for 1/16" +/-1/32" (Service Bulletins page 282).

Check also for king pin bushing wear. With tire/wheel off the ground (jack under axle) push in and out on the top and bottom of the wheel from the side to see how much wear there is.

Hope this helps.



.
__________________
Jim Cannon
"Have a Model A day!"
  • Repair
  • Restore
  • Drive
  • Enjoy!
  • Join MAFCA
http://tinyurl.com/Join-MAFCA
Jim/GA is offline   Reply With Quote
Old 09-06-2020, 09:14 PM   #4
GRutter
Senior Member
 
GRutter's Avatar
 
Join Date: Sep 2017
Location: Mint Hill, North Carolina
Posts: 162
Default Re: Wandering

If alignment and toe in is OK, then wandering from side to side would almost certainly be a sign of play in the steering linkages somewhere. (Note: Most alignment shops don't have a clue how to check the alignment on a model A, and modern computerized laser equipment doesn't have the settings entered to be able to align)

First, follow the guidance of Jim (Posting 3 above) to check toe-in and to look for play in the king pins and linkages.

The 7-tooth box does not have an adjustment for sector and worm mesh, and the bushings are subject to wear. With the front wheels raised off the ground, pull up and push down on the steering wheel to see if there is ANY up and down play in the steering shaft. Any up and down movement would allow your vehicle to wander, and is an indication of the bearings not being shimmed correctly.

I know you said you checked steering with a dial indicator.. not sure what you checked or under what conditions, as the only adjustment on the 7 tooth box is sector end play. You indicated that you checked in a vise... did you recently rebuild your steering box ?
GRutter is offline   Reply With Quote
Old 09-07-2020, 06:47 AM   #5
BRENT in 10-uh-C
Senior Member
 
BRENT in 10-uh-C's Avatar
 
Join Date: May 2010
Location: Eastern Tennessee
Posts: 9,514
Default Re: Wandering

While the answers above are all valid, the first place I generally go is to look at the front spring hangers (shackles) to see their position. When the spring has the correct arc, the hangers are more horizontal. The more the spring is worn, the more vertical the hangers will be between the perch and the spring eyes.

Next is to look at the front radius rod ball and socket to see how loose they are. If you can move it in any direction, it is too loose. Items like incorrect toe-in adjustment is what causes the axle to move laterally when the front spring or the radius rod is worn out of specs. This is why the vehicle wanders.
__________________
.

BRENT in 10-uh-C
.
www.model-a-ford.com
...(...Finally Updated!! )

.
BRENT in 10-uh-C is offline   Reply With Quote
Old 09-07-2020, 06:59 AM   #6
updraught
Senior Member
 
updraught's Avatar
 
Join Date: Feb 2015
Location: Australia
Posts: 1,425
Default Re: Wandering

Sponsored Links (Register now to hide all advertisements)
If something is stopping the self centering, I'd guess something is stiff.

It's sticking in one direction, then the other.

Assuming the caster is correct.
Easy enough to check if everything is moving freely.
updraught is offline   Reply With Quote
Old 09-07-2020, 07:08 AM   #7
WHN
Senior Member
 
Join Date: Mar 2017
Location: Connecticut Shoreline
Posts: 1,174
Default Re: Wandering

Drop the front end and check everything out. Not that big a job.

To me everything mentioned above is good advice but their all saying the same thing when you put the posts together. “It could be any of a number of things”.

Front end and brakes. They need to be right.

Enjoy.
WHN is offline   Reply With Quote
Old 09-07-2020, 09:53 AM   #8
Tacoma Bob
Senior Member
 
Tacoma Bob's Avatar
 
Join Date: May 2010
Location: Tacoma, WA
Posts: 900
Default Re: Wandering

I wrote a pdf format in the search above on my wandering issues. I chased this for several years. After replacing a lot of front end stuff and out of luck I figured out what it was. For me it was the spring perch nuts. The drivers side took two and a half turns to tighten and the passenger side took 3/4 of a turn. Once I "snugged em up"the car steers quite well.
Tacoma Bob is offline   Reply With Quote
Old 09-07-2020, 02:32 PM   #9
1931 flamingo
Senior Member
 
1931 flamingo's Avatar
 
Join Date: May 2010
Location: new britain,ct 06052
Posts: 8,704
Default Re: Wandering

Ck tire pressures also.
Paul in CT
1931 flamingo is offline   Reply With Quote
Old 09-07-2020, 04:29 PM   #10
Mad Mac
Senior Member
 
Join Date: Mar 2013
Location: New Zealand
Posts: 308
Default Re: Wandering

Thanks Guys,
Some really useful tips there. I will explore your ideas over the next few weeks and report on progress. I checked the play in the steering box by clamping the steering column in the vice, then clamping the steering wheel so it could not move, then measuring the movement in the pitman arm. The dial guage found only about 0.5 mm movement in the arm.
Mac

Last edited by Mad Mac; 09-07-2020 at 04:35 PM.
Mad Mac is offline   Reply With Quote
Old 09-08-2020, 09:02 AM   #11
1931 flamingo
Senior Member
 
1931 flamingo's Avatar
 
Join Date: May 2010
Location: new britain,ct 06052
Posts: 8,704
Default Re: Wandering

Besides tire pressure as I mentioned above, how OLD are the tires themselves??
Paul in CT
1931 flamingo is offline   Reply With Quote
Old 09-08-2020, 10:36 AM   #12
katy
Senior Member
 
katy's Avatar
 
Join Date: Jun 2015
Location: Alberta, Canada
Posts: 2,749
Default Re: Wandering

Quote:
I have established that there is no play at all in the 7-tooth steering box
If the steering box is adjusted too tight it will want to go off centre.
__________________
Play it again Sam.
katy is offline   Reply With Quote
Old 09-19-2020, 03:43 PM   #13
Mad Mac
Senior Member
 
Join Date: Mar 2013
Location: New Zealand
Posts: 308
Default Re: Wandering

Thanks again everyone for your helpful answers.
Thinking that tyres might be the problem, I swapped the front two tyres with two spares and pumped up all the tyres to 35psi. Result? Wandering problem gone!

Previously, when I checked the tyre pressures I found that three were only at 20psi and one was 33 psi, so that seems the most likely cause. However as I also swapped the two front tyres, I guess that could also have been a possible cause. Anyway, I am very pleased to have solved the problem without big expense.
Mad Mac is offline   Reply With Quote
Old 09-19-2020, 05:41 PM   #14
Jim/GA
Senior Member
 
Jim/GA's Avatar
 
Join Date: May 2010
Location: Young Harris, GA
Posts: 1,612
Default Re: Wandering

Thank you for posting what you found as the solution.



.
__________________
Jim Cannon
"Have a Model A day!"
  • Repair
  • Restore
  • Drive
  • Enjoy!
  • Join MAFCA
http://tinyurl.com/Join-MAFCA
Jim/GA is offline   Reply With Quote
Old 09-20-2020, 09:54 AM   #15
rotorwrench
Senior Member
 
rotorwrench's Avatar
 
Join Date: Jun 2010
Location: San Antonio, Texas
Posts: 11,950
Default Re: Wandering

The caster on the model A vehicles was fixed from the factory but is can change with heavy use and lots of bumpy roads over the years. Accidents can bend the axle and as was mentioned, the radius rod ball and socket can be worn to a frazzle. Caster and proper toe in are what keep cars from wandering around too much. Axles can get bent bad enough that caster and camber will both be off. The radius rod or axle can be adjusted to affect the caster.
rotorwrench is offline   Reply With Quote
Reply

Thread Tools
Display Modes

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off

Forum Jump

Sponsored Links (Register now to hide all advertisements)


All times are GMT -5. The time now is 12:14 AM.