This topic has been covered a few times before but since I have recently had personal experience with it I would like to emphasis the importance of changing out the stock lower A-Arm bolts with a stronger grade 8 bolts. I have done this on both the 700 twins I have owned but failed to do so on my wife's 05 500 HO. A few weeks ago a trail ride became a task to get her quad back to the truck after one of the stock bolts had broke causing the A-Arm to twist apart and become separated from the frame and wheel yoke. This can get serious if your 7 miles from the truck and up 12,000 feet on a OHV only trail in the Rocky Mountains of Colorado and darkness is setting in.

This is where the break down happened. Gunsight Pass


The broken A-Arm had to be bungeed down to keep the broken arm from dragging the side of the tire. The shock absorber first had to be removed and left off. At the top left you can see the half of the lower arm that remained intact. The bolt going through the big washer is the one that needs to be changed out with grade 8's. Total of four for both sides.



The local auto parts store (Auto Zone) only carried 3" long by 7/16 bolts. The length you need is 2 7/8". I had to use an addition grade 8 flat washer with grade 8 lock washer to make up for the longer bolt. If I hadn't the end of the bolt protrudes to far into the wheel yoke and could possibly rub the CV boot. I didn't want to cut the bolt because it was zinc coated and did not want to expose the raw steel. The grade 8 bolts were $.99 each w/ washer's. A cheap investment. A new A-Arm was $78, with other needed parts the bill came to $150.

If you havent changed out your bolts yet - It should be a priority for any Sportsman owner. I have a 335 and a 500 and it has happened to both and also my brothers 335.

The question isnt if it will happen, it is when will it happen. And it usually isnt at a very good time.

Plus if you wait till it happens you have to also drill out the old bolt and install a Helicoil to repair the threads. Helicoil kit - another $40.

Replace all bolts b4 they break - <$5

Good point about the heli-coil Callen. I was lucky the threads in the yoke wern't damaged. One thing I should have mentioned is that the stock bolts are loctite-ed in with blue locktite a medium grade. If your bolt is broke off flush like ours was, you will have to drill and use an easy-out to remove it. The blue locktite will soften up if you heat the yoke, making the broken bolt removal easier.

Broken bolt removed.


With the new grade 8 bolts be sure and re-apply some locktite. Those bolts will come loose.

Are those bolts the only ones to really worry about on the Sportsman?

I never had a problem with mine, but I bought the machine used with 7000 kms and I don't know if the previous owner did the upgrade or not.

I will seek to find grade 8 replacement bolts and replace them anyway. Better now than in the woods. I can then keep the old ones for spares.

Thanks for the warning Lewy.

Thanks for the info, sorry about your breakdown.

Would you suggest to replace the two bolts on the front lower a-arm too?

Thanks,
Hillton

I have not had any problems with any other suspension component bolts breaking. If I had the oppurtunity to change all the A-Arm connecting bolts to grade 8 bolts I would do so. Perhaps I shall this winter. IMO it could not hurt.

Hello all : Do you all think I should change the bolts on my 2006 Polaris 450 Sportsman ? Also woud these bolts still be the 2.875 long by .437 - 14 thread ( usa ) ? thank you all and this is still the best sight around .

dave1966 wrote:

Hello all : Do you all think I should change the bolts on my 2006 Polaris 450 Sportsman ? Also woud these bolts still be the 2.875 long by .437 - 14 thread ( usa ) ? thank you all and this is still the best sight around .

They are the same bolts on your 450. For $5 you can't go wrong.

PolBug wrote:

Are those bolts the only ones to really worry about on the Sportsman? I never had a problem with mine, but I bought the machine used with 7000 kms and I don't know if the previous owner did the upgrade or not. I will seek to find grade 8 replacement bolts and replace them anyway. Better now than in the woods. I can then keep the old ones for spares. Thanks for the warning Lewy.

The standard grade 5 bolt will have 3 lines on the head, spaced equally apart around the head radiating from the center of the head outwardly. The lines are about half as long as the distance from the center to the edge of the bolt head. A grade 8 bolt will have 6 lines on the head, equally spaced, the same length as the grade 5 bolts. The ones with 6 lines spaced evenly are the ones to use.
Avoid the bolts that have 6 lines arranged in a half-circle or half-moon shape on the bolt head. These are NOT the same as a true grade 8 bolt. They are hardened to about the same hardness, but are not ANNEALED like a true grade 8 bolt is, which means it is brittle, and cracks easily. They are cheaper than a regular grade 8 and are about as strong in a static environment (think holding building panels together) but can crack when put under shock loads (such as landing off a jump) The annealing of the true grade 8 bolts makes them FAR more crack resistant.

You got my attention, My question is, When you replace these bolts, what are the torque specs?

lowflyer43 wrote:

You got my attention, My question is, When you replace these bolts, what are the torque specs?

From the book, lower wheel bearing carrier bolt torque is 30ft.lbs. Personally I have never torqued the replacement bolts, just tightened by feel. I wouldn't know if additional torque is needed since the grade 8 bolts are stronger or if extra torque would increase shear strength.

Thanks for all the info farmr123 and lewy.

OK I had the wife order me 8 .437 x 14 x 2.875 grade 8 bolts today , they should be in by Friday . Thank again for the info keep up the good work

Crap that sucks I mud bog lots turning 29.5's, and have not had a problem. I have twisted 1 yoke and broken a few universals you should drill and tap some grease zerks into those controll arms on the outter the upper on the hub can also be drilled and tapped, of you had a 02 you are obviously aware of where they need to be a little grease will do wonders. I won't be changing mine anytime soon, none of the guys I ride with have ever broken one of those bolts, the ones on the front, on the lower controll arm is the ones we break.