Steering Lash

[jimmcld]

Just adjusted the steering lash on my M816. Made a world of difference. I had about four inches of play before, but now there is no noticeable play in the wheel at all. I just drove it on a rode that roles back and forth. This road gave me a hard time before. Now it's no problem.

 

[lsansone]

can you tell us how you did it? did you adjust the screw/nut combo on the forward part of the box?

thanks
lou

 

[jimmcld]

The instructions are in the 34-2. The only hard part was locating the adjusting screw. No, it is not the nut and screw on top of the unit. The adjusting screw is on the inside and pokes through the frame rail. It is just about even with the top screw, from front to back. However, if you lay your head on the front diff. looking up towards the left front of the truck, you can actually see it.

It does take a socket to loosen the lock nut and that makes it impossible to put a screwdriver on the screw. So, I just marked the position of the screw before loosening the lock nut. Then, after loosening the nut, I could use a screwdriver to turn the screw back to where it was, plus one turn. The one turn is pur the TM, and it worked out perfect. There is no noticeable increase in resistance when turning the wheel from lock to lock, and all the excess play is gone.

 

[lsansone]

thanks for the explanation. I did look through the manual, but must have missed it. my 817 has a about 2 1/2 inches of play and it would be nice to tighten it up a little

can you tell me exactly what section in 34-2 you found that info. i went through it again tonight and cannot find anything. greatly appreciated

lou

 

[kastein]

Another thing to keep an eye on is the bracket for the steering box. The one in my M54A2 w/ power steering worked loose at the frame end, all the rivets were stretched and loose. I have replaced one of them with a suitably sized grade 8 bolt and will be replacing the others as soon as I figure out what the best grade bolt to use is (matched to the strength of the metal it holds, like the rivets, or as strong as possible, i.e. grade 9 or 10?)

 

[jaxsof]

9 or 10? Umm, 8 is as good as it gets, SAE & ASTM Bolt Grade ID Marks & Properties Reference Table - Engineer's Handbook

 

[kastein]

huh, guess a friend of mine misinformed me... had never seen them myself. Grade 8 it is!

EDIT: maybe not. http://www.fastenal.com/web/product....e34RbhmQbxiOai0Nb350rQjwqQzOnh8?sku=11101606 grade 9 bolts here. No idea whose spec grade 9 is or whether it's actually worth it.

 

[jimmcld]

There are numerous bolts stronger than grade 8, but you probably won't find them at the local hardware store.

 

[jaxsof]

The problem with those "Stronger than Grade 8" bolts is there is no standard to back it up. ANSI and ASTM have only specified for a Grade 8.

and I quote "Engineer's Edge"
"Grade 12" is not a valid material condition or 'call out' to SAE, ASTM, or ASME specifications.Grade 8 is the highest standard 'western' material condition: ferrous alloy heat treated."Lamalloy L-9" is a proprietary alloy steel material heat treated that is somewhat 'stronger' than Grade 8.( 160m psi tensile vs 180m psi tensile)ISO metric materials are Class 12.9 (applies to hex socket head cap screws, equivalant to ANSI 'heat treated alloy steel' Rc38-45); Class 10.9 (applies to hex head cap screws, equivalant to Grade ; Class 8.8 (applies to hex head cap screws, equivalant to Grade 5)For tensile strengths over 180m psi uts, special manufacture in a variety of available materials and conditions are the norm. Jim DisharoonTranSpec Fasteners, Inc.

If you know of a "standard" that specifies a yield stronger than 180000psi, spit it out, dont just say that they are there. (A490 is the same spec as Grade
Also, doesn't anyone find it suspect that Fastenal's Grade 9 bolts arent "SAE Grade 9"?

But to the point, the strongest bolt isnt always the one you want. When that bolt fails toyeild, what is it going to cause to break in its place. There really is a reason why Grade 5 bolts are still specified for most applications. That extra 35,000 psi of proof load may be the difference in a broken bolt and a totally grenaded steering gear, and at 50 mph it makes a really big difference in the size of the dent.

 

[Coldfusion21]

Astm does list a spec for L9 hardware and other grades. SAE does not.

ASTM A574

As for tensile strength increasing brittleness I don't think any hardware spec is going to have a tensile strength so high as to make the fastener significantly more brittle.

 

[jaxsof]

Again, there is no ASTM or ANSI standard for L9. It is a trademark. As to the referenced ANSI (A574) standard, yes it has a higher ield and tensile strength han grade 8, but is strictly referencing socket head cap screws, not hex bolts. Kastein has the right idea, in that he is trying to match the fasteners' strength to the material it will be holding, as temperature changes affect strretch and the resulting strain on the fastener (they should expand at the same rate, to reduce the chance of squeezing the material/ stretching the fasteners resulting in a loose fit)

 

[kastein]

My apologies... did not mean to get this derail started

Any other causes of loose steering people know of?

 

[jimmcld]

I don't believe he specified ASTM or SAE bolts. For example: Nippon steel has produced a line of "Super high-strength bolts".

 

[jaxsof]

You can produce anything you want, and call it whatever you like, but if there is no standard to back it up, it may as well have come from a sweat shop in China.