Finally got the Boise Springs on!

[Ken]

Well it took me just under a year to get around to putting on the Boise Spring Kit. Actually it took me that long to finally get around to having all the clunks and noises fixed by the dealer. Anyway the springs are on and the T-Bars are cranked.

Over all on the rear is just a hair over a 2" lift and the front came out to 1.25". It took me 5 full turns on the t-bar to get that 1 1/4 lift. On the rt side the bolt is just about to bottom out (maybe room for 1 more turn). Does this sound like a lot of turns to only net 1 1/4"?

I was hopping for at least 1.5" in the front but stopped at 1.25". As of now the truck has a .75" "rake/slope" from front to back however it does not look bad. I know the rear will settle some maybe a .25" - .50" so it should be fine.

I could give each bolt one more full turn and that would get me close to 1.5" what do you guy's think? Play it safer with c/v boots etc. and stay at 1.25" or take it up another .25" to try and get closer to level.

[Retep]

Wow, I thought I was slow after letting my Boise springs sit on the garage floor for six months before I installed them.

Mine settled to 1.5 inches after a couple months. .75 rake is fine. Mine is a little more, but I like a little rake on a truck.

Be careful with that much t-bar crank. Some may say its too much and some will say its fine. I will just say be careful. I had an inner cv boot start spitting grease after a .75 inch crank. It seems the S trucks differ from each other on how they react to a t-bar crank. Some have boot problems at stock z height settings while others can crank and crank without any negative affects. Just keep an eye on the boots.

How is your ride after the new springs? Mine turned out a little firmer than I had expected. Some day I will get some Bilstien shocks which I think will help.

Enjoy the springs. The first time you haul a heavy load or pull a trailer you will wonder how you ever did without them.

Pete

[HenryJ]

Congrats on your patience

There is no way I would have been able to last that long.

The rear springs will settle some and I wouldn't get too worried about the T-bar crank. The torsion bars settle too. After four years of moderate use, I don't think that you could over crank them.

Pete has it right , they really shine when towing a load.

[Ken]

How is your ride after the new springs? Mine turned out a little firmer than I had expected.
Pete

The ride is great, it actually feels like a truck now. These trucks were soft and sloppy from the factory, Shocks helped a lot but this really stiffened it up. In reality it is stiffer than I would like if I could "hand select" the feel. It's a battle, between sitting too low and the ride too stiff. I would rather have the height and the stiffness than set too low (factory).

Besides my step bars actually look like they serve a purpose now.

I did notice a vibration that I do not believe was there prior to the lift. I was wondering, since lifting the truck 2" how much does that change the working angle on the u-joints? Has anyone taken the time to check that? Also I know "they" make a wedge/block that goes between the diff and springs that allows the diff to be "pitched" upward in order to correct/adjust u-joint working angle's. Has anyone looked into this either? I feel fairly certain that given the symptoms of this vibration that it might be related to driveline and the only thing that would have changed there is the "working angle".

[HenryJ]

I did notice a vibration that I do not believe was there prior to the lift. I was wondering, since lifting the truck 2" how much does that change the working angle on the u-joints? Has anyone taken the time to check that? Also I know "they" make a wedge/block that goes between the diff and springs that allows the diff to be "pitched" upward in order to correct/adjust u-joint working angle's. Has anyone looked into this either? I feel fairly certain that given the symptoms of this vibration that it might be related to driveline and the only thing that would have changed there is the "working angle".

With a spring lift like this the pinion angle stays the same. This is better as the tailshaft and pinion should remain parallel to prevent vibration issues.

Is there any chance that you may have a bad u-joint? The change may have been just enough to get it to show up?

You might also check the thrust angle. Mellowyellow's truck was off a little when we went in for the alignment. Not enough to warrant loosening the u-bolts to shift the axle housing, but maybe yours is? Might be worth having an alignment shop take a look?

[Retep]

...With a spring lift like this the pinion angle stays the same.

Does it??? I thought a spring lift like this would increase the pinion angle as you are lowering the axle relative to the transmission, thus increasing the pinion angle. Maybe I have it wrong, but thats how I understand it.

My Boise spring did not cause any vibration.

[HenryJ]

...With a spring lift like this the pinion angle stays the same.

...I thought a spring lift like this would increase the pinion angle as you are lowering the axle relative to the transmission, thus increasing the pinion angle. Maybe I have it wrong, but thats how I understand it....

The driveshaft angle does increase, but the pinion stays level. Lower but the same level.
Shackles do change the pinion angle, as would adding wedges.

[Ken]

I don't know for sure if my problem is drive shaft related or not. However I do believe that u-joint working angle is important and relative to us once the spring lift is performed. When the angle of the drive shaft changes that changes u-joint "working angle". By doing the spring lift we have raised the transmission in relation to the rear diff. The drive shaft is now leaving the trans and entering the rear diff at a steeper angle. I don't know if that angle is/would cause a problem or not. I use to have access to a inclinometer to measure the angle but no longer do. Does anyone here have access? Don't get me wrong, I know we haven't raise the truck a lot but for my peace of mind I would like to know where I stand on this.

I tracked some info down off of a website that explains this. Sorry for the long post.

Angles
Universal joints require a minimum working angle in order to properly lubricate the needle bearings of the joint. The U-joint has a maximum working angle which is determined by the rotational speed of the prop shaft. In other words, we need a little working angle for the U-joint or it will bernell and prematurely fail. We cannot handle too much angle or a vibration and joint failure will occur. As the shaft turns, the U-joints speed up and slow down the propshaft twice per rotation (a second order vibration). The steeper the working angle, the greater the speed changes in the shaft will be, thus, the greater the vibration.

That leads us to the question, "What is the maximum working angle for the shaft?" This could range from as high as 11-1/2° for a shaft rotating at 1,500 rpm to as low as 3-1/2° for a shaft rotating at 5,000 rpm. Generally, for the applications we deal with we would like to see a minimum of 1/2° to a maximum of 5° for the typical passenger car or light truck.

To check U-joint working angles, we need an inclinometer. This is a relatively inexpensive tool (generally around $50-$80) and you will find it will pay for itself the first time you use it.


To check working angle, simply rotate the shaft in question until a U-joint is pointing straight down. Attach the inclinometer and move the gauge until the bubble is centered. Note the reading on the tool. Remove the tool, rotate the shaft 90°, reattach the tool to the U-joint cap and center the bubble. Note the reading now on the gauge. To determine the angle, simply subtract the larger of the two readings from the smaller one. See Figure 3.

The above procedure is followed for all joints on all shafts. As each working angle is determined, keep this information in mind:
• Joints on opposite ends of a shaft should be within a 1/2° working angle of each other;

• On shafts with only one U-joint, the angle of that joint should be 1/4 to 1/2°;

• We have been measuring the longitudinal angles only. The other angle the shaft may have is called its lateral angle. This angle represents the amount of sideways offset of the propshaft in the vehicle. Vans are a good example of this. To make room for the driver’s feet, the powertrain is offset to the passenger side of the vehicle. It is possible to have both angles within specs but yet have a vibration from an excessive combination of the two angles known as the "equivalent angle." (Note: Lateral angle is a visual measurement, as typical shop tools are unable to calculate this angle.);

• Changing the angle at one end of the shaft also will affect the angle at the other end of the shaft, so double check all U-joint working angles;

• When dealing with a "launch shudder" concern, keep in mind that the static angles may appear okay. But remember, the nose of the rear axle rotates upward toward the vehicle floor pan when load and engine torque are applied. This must be taken into consideration when working on launch complaints; and

• U-joint angles are checked with the vehicle level and loaded with a weight comparable to the weight it normally carries.

U-joint angle concerns are addressed differently based on the type of rear suspension on the vehicle:

• Coil spring rear suspension - The rear working angle is adjusted on these vehicles typically by replacing the upper control arms for the rear suspension. Most manufacturers make different length upper control arms to allow you to position the nose of the rear axle where you need it.

• Leaf spring rear suspension - The rear working angle is adjusted on these vehicles by placing a tapered shim between the axle spring pad and the leaf spring. Which side of the rear axle you insert the tapered shim under is determined by which direction you want to move the angle, as well as which side of the rear axle the spring pad is mounted to. Tapered shims are available in different offset values from both the OEM as well as the aftermarket. (Note: If you are using a large offset/degree shim, be aware the center bolts’ heads will need to be extended or the axle may shift position causing a thrust angle/tire wear concern);

• Front joint angles are also adjustable. To raise the angle simply install a shim between the trans/transfer case mount and the cross member. Cross member shims are available from both OEM and aftermarket sources. To lower the angle it may be necessary to drop the position of the cross member lower in the vehicle. Shims are not available for this purpose so you will need to fabricate spacers to do the job.

[Ken]

Well it didn't take long. Less than a month and fewer than 700 miles but the Rt inner CV is slinging grease . Coming out from under the inner clamp. Off to the dealer for what I'm sure will become a regular occurence. I just wonder how many times they'll warranty it before realizing I crank the T-bars . Oh well I needed to take it in anyway because I have developed a engine noise that I feel sure is the timing chain rattle noise. Hey, its got 14,000 miles on it now; they don't last forever don't you know.

[HenryJ]

...Rt inner CV is slinging grease... Off to the dealer ... I have developed a engine noise that I feel sure is the timing chain rattle noise....

Keep us apprised of your experience. I will be curious to see if they refer to the phantom "special Z height measurements".

Also, rumor has it that the tensioner kit is no longer used due to its lack of lifespan. I have heard of no other "fix" and most are deeming it a "normal" and non destructive characteristic of this engine.

Let us all know what you find out.

[Spawn]

I may seem out of place in this forum, but would a Boise Spring kit ift on a 95 4dr s10 blazerI need a little more lift in back for my spare tire rack and spare tire and what ever hi-lift I get. I'm also getting fiberglass fenders from glassworks. Thanks for your time.

[HenryJ]

I may seem out of place in this forum, but would a Boise Spring kit ift on a 95 4dr s10 blazer...

I think it would, but check out this thread- Boise Springworks Kit (Question For HenryJ)
You're probably best to check your local spring shops.

[Ken]

...Rt inner CV is slinging grease... Off to the dealer ... I have developed a engine noise that I feel sure is the timing chain rattle noise....

Keep us apprised of your experience. I will be curious to see if they refer to the phantom "special Z height measurements".

Also, rumor has it that the tensioner kit is no longer used due to its lack of lifespan. I have heard of no other "fix" and most are deeming it a "normal" and non destructive characteristic of this engine.

Let us all know what you find out.

Took the truck in last Wed. and got the rt inner tripod boot replaced and the rt lower ball joint replaced (grease seal split). They did go ahead and install the timing chain tensioner. I got a copy of the bulletin from the tech, it is dated March 2004. I'm not sure if this is a "new" bulletin or not. But according to the tech GM was calling this a "Normal" condition at least up until March 2004. It could be that there was a prior version of a bulletin/tensioner kit that GM was using then stopped for some reason and is now using this one from March 2004?????

It did make a huge difference in reducing the eng noise. We will see how long the new boot holds up.

[coreylubahn]

So other than climbing under the truck and looking for leaking seals, CV boots, etc. is there any way of knowing if they are going bad? I always think my truck works like a charm and runs like a dream, but it seems almost everyone here has the same problems and maybe I have them but just don't know it?