Foretravel Owners' Forum

Foretravel Motorhome Forums => Foretravel Tech Talk => Topic started by: Jon H on October 14, 2018, 12:03:28 am

Title: Toe-in specs for 1995 U300
Post by: Jon H on October 14, 2018, 12:03:28 am
Anyone have the toe-in specs in inches for the U300.  Have read thru all the posts and have found it in degrees - but not inches. Trying to improve a slight wandering condition.

Thanks,

Jon
Title: Re: Toe-in specs for 1995 U300
Post by: Tom Lang on October 14, 2018, 12:09:24 am
I just called a James Triana to get my specs.

Mine is a 2003 U295, but likely the same. My specs are 0 to 1/16" toe, but I had it increased from 0 to 1/8"  And I like it this way. My mechanic also replaced the slightly worn drag link ball ends.

Big improvement.
Title: Re: Toe-in specs for 1995 U300
Post by: oldguy on October 14, 2018, 12:20:43 am
I like 1/8 to 3/16 toe in
Title: Re: Toe-in specs for 1995 U300
Post by: Hans&Marjet on October 14, 2018, 12:49:59 pm
Anyone have the toe-in specs in inches for the U300.  Have read thru all the posts and have found it in degrees - but not inches. Trying to improve a slight wandering condition.

Thanks,

Jon
Jon...lift up the dash panel above the instrument cluster..the specs are written there on a sheet of paper.

Hans
Title: Re: Toe-in specs for 1995 U300
Post by: Chuck Pearson on October 15, 2018, 07:52:19 pm
I'd be interested to know what the toe in spec in degrees is for my 96 U295.  Without knowing where toe in is supposed to be measured from the fractional measurement is useless. 

Is it 3/16" toe in per wheel from centerline?  Or per tire from centerline?  Or total toe in between both front tires?  Or total toe between both front wheel rims?  It makes a huge difference.



Title: Re: Toe-in specs for 1995 U300
Post by: craneman on October 15, 2018, 08:21:33 pm
Toe in is measured from the center of the tire straight forward and the center of the tire straight back.
Title: Re: Toe-in specs for 1995 U300
Post by: Chuck Pearson on October 15, 2018, 08:37:41 pm
Would appreciate the measurement in degrees if anyone has it.
Title: Re: Toe-in specs for 1995 U300
Post by: Protech Racing on October 15, 2018, 08:39:43 pm
1/4 in total at 40 in. Do the math if you have  to.   
On 40 in tire is about .35degrees.  total. But do your own math  please just to get it right. 

Convert Toe Inches to Degrees (https://robrobinette.com/ConvertToeInchesToDegrees.htm)
Title: Re: Toe-in specs for 1995 U300
Post by: Chuck Pearson on October 15, 2018, 08:50:41 pm
Would appreciate the spec in degrees if anyone has it. 
Title: Re: Toe-in specs for 1995 U300
Post by: Old Knucklehead on October 15, 2018, 10:41:52 pm
Here's a look at my '95s numbers from under the dash. Not degrees, but...
Title: Re: Toe-in specs for 1995 U300
Post by: Chuck Pearson on October 16, 2018, 07:44:33 am


Appreciate it everyone, but would still like to get the official, hopefully Meritor, specification in degrees for toe in.  Here's the reason....it's become apparent that there are several accepted ways of measuring toe in. 

So, referencing the tag under dash, calling for 1/8" toe, is this per wheel, giving total toe in of 1/4" as measured from rim to rim, or is it 1/8" total i.e. 1/16" per wheel?

Or,  is it 1/8" from centerrline of each  tire?  The larger diameter of tires as compared to wheels makes this a radically different amount than if measured from wheels (rims). 

I have  no clue how Foretravel measured it, or rather their longtime alignment guy Wayne, or how that compared to Meritor's spec, if any. 

The original spec in degrees will not be dependent on measuring points, finding centerlines of tires etc.  It will give the angle of each front wheel.  This can then be converted to a fractional measurement which will vary depending on where you wish to measure....centerlines of tires, wheel rims, etc.  So, in essence, this will yield 1/2 of total toe in of vehicle as measured between two fronts. 

PS, if anyone is watching videos suggesting pulling strings and measuring toe in, forget about it.  Even if it was possible to accurately do it's not necessary as the non ifs foretravels use a track bar....any adjustment affects both fronts equally.









Title: Re: Toe-in specs for 1995 U300
Post by: craneman on October 16, 2018, 08:56:14 am
When my trucks were aligned they always used center of tire front and rear for the toe. It would be impractical to try to use the wheel or any other method.. They had a large press that would actually bend the axle for camber, which mine never needed.
Title: Re: Toe-in specs for 1995 U300
Post by: Protech Racing on October 16, 2018, 09:25:30 am
 The reality is that you should use a little toe in as possible.  If the customer complains about wander you add a little , simple as that.  The high value  is 1/2 in  total toe . The low value is 0.
  My Oshkosh was zero when I got it and it drove fine on small ,high pressure tires.  I changed tires to the 295 and now it likes 1/4 toe in , measured  with toe plates  across the entire tire. Just above the bottom rubber bump.  Some can measure across the tire tread section that runs  straight 360*.
It does not matter how you measure toe as long as you use the same method each time. The mission is to have a bus that tracks well for the driver,  while using as little toe in as possible . Too much toe slows it down/burns fuel/ wears tires.
 Every vehicle has a tolerance stack  that affects tracking. Ball joint not new but inside of specs, kingpins, tie rods, wheel bearings ,  trailing links, etc, all can be in factory spec ranges , yet  all have some affect on tracking . Adding toe in can take up the total slack  in these items and produce the best compromise between driver and tire wear.

 If you get aligned at a shop,  ask to see that chart for your chassis, baring that, look for another bus that has the same front axle and start with those values. If it tracks poorly , ask for another twist of toe. Measure it post adjustment and use that value and measurement method for the future. .   
Title: Re: Toe-in specs for 1995 U300
Post by: Chuck Pearson on October 16, 2018, 09:54:22 am
Thanks Mike, I've got it set where I was happy, went that way after paying for two alignments that did nothing.  I took matters in my own hands after acquiring coach and putting on Michelins.  Toe in ended up being right at your high range, never noticed any problems and tires were unscalloped on edges when replaced after 6 years and 70K.  The Toyos I replaced them with have more defined ribs, directional stability, but don't like as much toe which is noticeable when cornering.  So, I'm starting the adjustment process again and was wanting the official toe recommendation for a baseline setting to work off of. 

So, call it academic curiosity but I'll end up setting them where I'm happy anyway.
Title: Re: Toe-in specs for 1995 U300
Post by: Racedad on October 16, 2018, 09:56:17 am
Toe is a function of tire diameter and the lateral movement of that tire over one revolution. The measurement is in degrees in an engineering world. In the real world Mike is correct. The following link has a calculator to convert degrees to inches.
Convert Toe Degrees to Inches (https://robrobinette.com/ConvertToeDegreesToInches.htm)
Title: Re: Toe-in specs for 1995 U300
Post by: craneman on October 16, 2018, 10:01:05 am
Toe is a function of tire diameter and the lateral movement of that tire over one revolution. The measurement is in degrees in an engineering world. In the real world Mike is correct. The following link has a calculator to convert degrees to inches.
Convert Toe Degrees to Inches (https://robrobinette.com/ConvertToeDegreesToInches.htm)
Thanks,
That link also gave other links on the page that I found interesting.
Title: Re: Toe-in specs for 1995 U300
Post by: Chuck Pearson on October 16, 2018, 10:35:23 am
Toe is a function of tire diameter and the lateral movement of that tire over one revolution. The measurement is in degrees in an engineering world. In the real world Mike is correct. The following link has a calculator to convert degrees to inches.
Convert Toe Degrees to Inches (https://robrobinette.com/ConvertToeDegreesToInches.htm)

No argument with any of this other than as I see it it's a measurement of lateral movement over 1/2 revolution.  After a full revolution it's zero. And that's not considering  the effect of camber on lateral measurement.  :D

I suspect but don't know for sure that alignment machines use degrees rather than fractional measurements, my hope was to find the oem recommendation in degrees to eliminate the variables of measuring points etc and establish a baseline.  But in the end it probably doesn't matter because I'll tweak it until I'm happy with the way it drives.  The proof of the pudding is in the eating as they say. 






Title: Re: Toe-in specs for 1995 U300
Post by: stump on October 16, 2018, 11:22:36 am
Mine felt loose in the front I measure across the middle  front of tire to other side then the same in back of tire. Measurement was the same added 1/8 toe difference from front to back way big improvement. Do not have any idea of how many degrees it would be. Zero degrees would sill be the same measurement front to back as with a tape.
I found this
Convert Toe Inches to Degrees (https://robrobinette.com/ConvertToeInchesToDegrees.htm)