Update on frame modification and MS2 tires

[booster]

Just a quick update on my frame mod to increase caster and camber increase of usable setting range, plus our Michelin LTX MS2 17" tire conversion. We just got home from about a 900 mile trip to the upper peninsula of Michigan all the way to Copper Harbor. Less than 100 miles of it on the freeway, so lots of two lane roads of various quality and speed limits of 55 or 65mph. Tire pressure was set at 63-77 psi at 70* before we left and we say near 80* going and as low 41* coming back. The return was a really good handling test as it had rains from light to heavy and 20+mph winds with gusts to 35 mph. Lots of gusts from varying directions.

The frame mod was to let me get more caster and to center the right side wheel in the wheelwell which it was not from the factory and also could not get past a bit over 3* of caster. Definitely a factory defect. I moved 3 of the 4 lower control arm mounting holes in the frame to turn the lower control arm to get the lower balljoint further forward and further inboard. Welded in plugs in old holes and redrilled new holes that overlapped the old holes to move about 5/8 of an inch at the balljoint forward and 1/4" inboard. I then added doublers to all the holes to reinforce the repaired area as assurance of strength and durability. All repairs fully welded in.

I set the alignment (I do my own in the driveway) at +6* caster both sides, -1/8* camber, and 1/8" toe in.

The van had handled very will before the changes but got even better, particularly at 55mph and under when more caster shows up the most. It handled 65mph two lane roads with rumbles very close on both sides in wet and extremely windy conditions without being hard to drive at all. Certainly not like no wind and dry but not by a whole lot. The temp was 41*-45* so tire pressures lower but felt better than at 80* so will be reducing set pressures going forward.

Tires are Michelin LTX MS2 265/70/17 on 2000-2010 GMC Sierra pickup aluminum wheels the +28 offset so right at original offset for the van.

Very happy with both the frame mod and the tire and wheel change to 17".

 

[jjrbus]

I have been patiently waiting for this update and was hoping for some pictures. Glad it worked out well for you and that you are happy with it. I am still in limbo and not sure what to do with mine due to the fact that other than you I can find no one to talk to about doing the LCA mount mods.

Now looking for a shop with a laser frame machine to have it inspected one more time.

 

[booster]

I don't have extensive pix like I would normally have because I was had the bicep, rotator cuff issues slowing me down to about 1/4 speed on everything, and then when the surgery got scheduled so quickly time got extremely tight to get it done and mostly back together and not have to pick it all up again months later.

I did find 4 that kind of show the process I wound up with after several restarts so I could get them all in line well enough and in the right place also.

 

[booster]

At first I laid out the move and planned on grinding it to correct location and welding in a small patch, but found the hole has to be sized better than that to prevent movement under the large loads of driving.

I then just windowed that hole larger so my aligning tool could easily get through it. This is the second from the front hole and the third from the front was not going to move so put tool through that as starting point. I had put some reference scribe lines where I wanted the hole out of the pic so I could find it again and held the tool there while marking it closer and through the hole to correct vertical height at the first hole still in the frame as original. I put in new scribe lines for the desired place for the second to the front hole and cut the patch for it by hand and tacked it in place well. I extended the scribe lines onto the patch and center punched the location before drilling and final filing the hole to size.

At this point I had two holes, 2 and 3, with the right size hole and in the right place so the hard part was done in regard to location. I made patches for the two holes that were left after grinding out the holes big enough so a patch would have enough welding space outside of the hole itself area. Tacked in the patches and used the tool with a center punch insert on the end to go through the two holes and center punch the last two locations so I could drill and size them. I checked with a longer tool the same size to make sure they were in line and then finished welding them in shooting for near 100% penetration.

I then assembled the control arms without the spring and supported them with a jack to ride height and did a quick alignment check to see if I was within range, which I was.

I then made doubler plates for all 4 holes that went on the non arm side of the holes. I put holes in the plates ahead of time of the same size as the frame and used a big bolt to hold them in places as I welded them all in place around the perimeters. No pic but are still visible with wheel off so can get one later.

I then put it back together until I was healed up enough to get it in the driveway to align. Then back into the garage for final multiple times tightening of the 140ft-lb spec bolts with the centering tapered centering washers on all 4 holes instead of just on the nut end like the factory had them.

 

[Deano-ClassB]

I envy you!

 

[jjrbus]

Quite an accomplishment recovering from surgery. Wish I could have been there to hand you tools. My 01 had the centering washer on each end of the bolt.

 

[booster]

Quite an accomplishment recovering from surgery. Wish I could have been there to hand you tools. My 01 had the centering washer on each end of the bolt.

I was surprised ours weren't on both ends, but I think GM found out, or arbitrarily decided, that only the threads hitting the frame was the problem and only did the thread end.

The tapered end of the washer swages into the hole so the bolt doesn't hit the frame material to damage it. The washers are very hard and the bolts slightly less hard so wear will be negligible as long as they are very tight, I think.

My issue to decide on was it it was wise to put the washers on outside of the reinforcing plates I added. Since then the plates would pick up all the load and transfer it to the frame. I chose to oversize the bore of the plates to be a loose slip fit on the washer OD so they would still put the load on the frame directly with the very close fit of the washer in doubler plate as backup or minor load absorption if needed.

 

[jjrbus]

I was surprised ours weren't on both ends, but I think GM found out, or arbitrarily decided, that only the threads hitting the frame was the problem and only did the thread end.

The tapered end of the washer swages into the hole so the bolt doesn't hit the frame material to damage it. The washers are very hard and the bolts slightly less hard so wear will be negligible as long as they are very tight, I think.

My issue to decide on was it it was wise to put the washers on outside of the reinforcing plates I added. Since then the plates would pick up all the load and transfer it to the frame. I chose to oversize the bore of the plates to be a loose slip fit on the washer OD so they would still put the load on the frame directly with the very close fit of the washer in doubler plate as backup or minor load absorption if needed.

When I did mine it said to check that the LCA bolt holes were within ?? thousands of an inch. I do not remember the spec but it was a small number.

I have been to 2 collision supply stores and a couple collision shops, finding a shop with a laser frame machine is not going well.

 

[booster]

When I did mine it said to check that the LCA bolt holes were within ?? thousands of an inch. I do not remember the spec but it was a small number.

I have been to 2 collision supply stores and a couple collision shops, finding a shop with a laser frame machine is not going well.

I can believe that as it a very specialized operation.

Plus, I am not certain that a laser machine would be able to do what you need to do without the frame being loose with no body on it.

You need to measure the location of the upper control arm mount holes and lower control arm holes in both the fore and aft and crosswise directions. Laser would have shoot through the wheelwell with all the suspension removed to do that.

It may be that the alignment limits you are seeing is enough to do the changes needed. That is what I used for a baseline and used basic trigonometry to calc out how much things needed to move. I was quite close, as it turned out.

You might want to check with a shop that modifies pickups and SUVs for offroad as they move stuff around all the time.

 

[jjrbus]

I can believe that as it a very specialized operation.

Plus, I am not certain that a laser machine would be able to do what you need to do without the frame being loose with no body on it.

You need to measure the location of the upper control arm mount holes and lower control arm holes in both the fore and aft and crosswise directions. Laser would have shoot through the wheelwell with all the suspension removed to do that.

It may be that the alignment limits you are seeing is enough to do the changes needed. That is what I used for a baseline and used basic trigonometry to calc out how much things needed to move. I was quite close, as it turned out.

You might want to check with a shop that modifies pickups and SUVs for offroad as they move stuff around all the time.

No progress so far finding a laser frame machine. Stopped by what seems to be the top off road shop in the area and he said he would not deal with it as he is unfamiliar with the platform. He did take my name and number in case he thinks of anyone that might be of help to me.

Mulling this over and I do not see much difference between using an offset ball joint or bushing and moving the control arm bracket hole or the entire bracket.

 

[booster]

No progress so far finding a laser frame machine. Stopped by what seems to be the top off road shop in the area and he said he would not deal with it as he is unfamiliar with the platform. He did take my name and number in case he thinks of anyone that might be of help to me.

Mulling this over and I do not see much difference between using an offset ball joint or bushing and moving the control arm bracket hole or the entire bracket.

I have never seen an offset balljoint and can't imagine how they could function, especially on a heavy vehicle. I have seen offset locations welded into an upper control arm after cutting off the original one. If it has to move only a small amount the hole can be plugged and redrilled, but that isn't commonly the case.

Moving the holes is what I did so the thread discusses that.

But, you might be able to find someone to modify the upper control arms themselves, preferably a spare set just in case it doesn't work. That is what I did on my Buick wagon that has similar fabricated arms, I think. Material can be remove or added to upper arm to get what you need. The Buick is less weight and lot less tall at 5000# and normal car height, but the process is the same. You need a good shop to do it. Offroad shops do some of that kind of modification, but it sounds like the on you found didn't want to mess with it. I might have thread on the GM longroof forum with description and pix, I will look for it. The welding and material used quality needs to be very good to be strong enough, so need a good place. Not a job for an inexperienced fabricator/welder. Of course is you find someone who could fit the pieces and tack weld them, you could take them to a certified welder and be sure of good welds.

 

[jjrbus]

I have never seen an offset balljoint and can't imagine how they could function, especially on a heavy vehicle. I have seen offset locations welded into an upper control arm after cutting off the original one. If it has to move only a small amount the hole can be plugged and redrilled, but that isn't commonly the case.

Moving the holes is what I did so the thread discusses that.

But, you might be able to find someone to modify the upper control arms themselves, preferably a spare set just in case it doesn't work. That is what I did on my Buick wagon that has similar fabricated arms, I think. Material can be remove or added to upper arm to get what you need. The Buick is less weight and lot less tall at 5000# and normal car height, but the process is the same. You need a good shop to do it. Offroad shops do some of that kind of modification, but it sounds like the on you found didn't want to mess with it. I might have thread on the GM longroof forum with description and pix, I will look for it. The welding and material used quality needs to be very good to be strong enough, so need a good place. Not a job for an inexperienced fabricator/welder. Of course is you find someone who could fit the pieces and tack weld them, you could take them to a certified welder and be sure of good welds.

Thanks for the response. Out of the forums I have posted on you are the only person that has ever responded with any positive input. I am going to try a couple more off road shops hoping to find someone that will work on this.

 

[booster]

Thanks for the response. Out of the forums I have posted on you are the only person that has ever responded with any positive input. I am going to try a couple more off road shops hoping to find someone that will work on this.

Be aware that I am somewhat famous (maybe infamous) for taking on stuff like this just because everybody says you can't do it at home in your garage. I decided to build a twin turbo V8 street Challenger at home when everybody said it was impossible because even the best speed shop hotrod companies were having trouble with building driveable street vehicles with high boost. It took one year to sort out head gasket issues but then I ran the car and it's updates for 30 years.

It is is doable, as I have done it on two street vehicles, my Buick and the Roadtrek, but it is high risk so many shops are scared of the liability issues, I think.

 

[jjrbus]

Be aware that I am somewhat famous (maybe infamous) for taking on stuff like this just because everybody says you can't do it at home in your garage. I decided to build a twin turbo V8 street Challenger at home when everybody said it was impossible because even the best speed shop hotrod companies were having trouble with building driveable street vehicles with high boost. It took one year to sort out head gasket issues but then I ran the car and it's updates for 30 years.

It is is doable, as I have done it on two street vehicles, my Buick and the Roadtrek, but it is high risk so many shops are scared of the liability issues, I think.

25 years ago I did a bus conversion and was an active member of the conversion community. Those people were amazing and you would have fit right in. My budd Gerald was a self taught engineer and retired from GM tech center, I know he could do this in his driveway but is 80+ now and not very communicative. Not many Geralds left in this world.