1990 FJ62 stock to parabolics fixing vibrations

[cruiserpants]

O.k. a I'll bite with few questions:

"My rear flanges are 3 degrees off of perpendicular to the ground each, hence equal angles."

When you say equal angles: Do you mean that if the trans flange is pointing 3 degrees downward then the pinion flange is also 3 degrees downward?
(in which case it would be wrong and create a bad vibration)

Also, what range do you feel the vibration(MPH) ?

A 6" lift on a FJ62 (auto trans) is going to require axle shims - period.

 

[Hank]

The T-case is 3 deg up actually as in the bottom of the flange is closer to the rear of the truck than the top. The bottom of the flange on the rear end is closer to the front of the truck than the top. Vibe starts at 20mph and goes to 30 mph really bad then not so bad and then towards 50 I want to get out NOW!

I tend to agree with your last statement but the manufacturer disagrees. I'm going to make sure there are no other variables that I am missing before I shim it. Thanks

 

[Cruiserdrew]

I apologize for not reading the whole thread, but when I lifted my 60 I got major vibes that I thought was driveline angle in the rear. Once I chased it all down, it turns out the pinion bearing was bad. Worked OK with no lift, but once the lift was in it was quite noticable.

Check and see if there is any up and down slop at the pinion, then check to see if the pinion nut is loose. If it is, that usually means the bearing is worn. The solution is a diff rebuild with new bearings.

Are you certain the rear t-case out put and the diff flange are parallel? A drive shaft vibe from improper alignemnt would still be the most common problem. I assume you checked the phasing as well.

 

[Hank]

I apologize for not reading the whole thread, but when I lifted my 60 I got major vibes that I thought was driveline angle in the rear. Once I chased it all down, it turns out the pinion bearing was bad. Worked OK with no lift, but once the lift was in it was quite noticable.

Check and see if there is any up and down slop at the pinion, then check to see if the pinion nut is loose. If it is, that usually means the bearing is worn. The solution is a diff rebuild with new bearings.

Are you certain the rear t-case out put and the diff flange are parallel? A drive shaft vibe from improper alignemnt would still be the most common problem. I assume you checked the phasing as well.

Rear end has already been rebuilt, pinion nut is tight, pinion is tight,bearings are good. Phase is good, flanges good. I'm hoping to get some time this weekend to get back in to the issue. I'm going to put in GMB joints and have the shaft balanced and retorque everything for the 2nd time.

 

[euclid]

I didn't read the whole thread either, but here's where I've found vibes in the past:
1. pinion
2. bad u-joints. I've tried every single brand out there. OEM is the only way to go.
3. Shims to make the pinion angle right. I actually turned my rear a bit when I installed the FF. Incidently, I really like how mine drives with 4* shims on the front too.
4. All the above is after I verify that I don't have vibes in the tires. Don't assume that it isn't in your tires because it didn't vibrate before the lift. You had the tires off of the truck, you could have lost a weight.
5. Alignment. You would likely feel it more in the steering wheel if this was the case.

 

[Pacer]

The T-case is 3 deg up actually as in the bottom of the flange is closer to the rear of the truck than the top. The bottom of the flange on the rear end is closer to the front of the truck than the top.

This sounds strange to me....

\====/

I sounds like you are telling us that your TCase flange is at 3* and that your DriveShaft flange is at 3* but in opposite directions. Just to be clear, is your pinion pointing down slightly and your TCase output pointing up slightly? Even though the angles match it sounds like there sum would be 6* out of parallel at ride hight.

I agree with the masses so far, I say shims are critical with this amount of lift.
YMMV

best of luck and thank you for the detailed description. I'm glad the parabolics are comfortable.

 

[ad20k]

Any updates Hank? Still vibratin'?

 

[iaintscared1969]

I have had this occur on a H**p I had worked on with 6" of lift. Although the driveshaft and pinion angles looked to be good. I pulled the rear D-shaft and had a CV shaft made up for it. Took care of the problem. More cruiser related my 62 has HFS 4" lift. The adapter they provided for the tranny and transfer case to remain in stock location caused enough deviation from the driveline angle for it to shake the truck like it was rattling apart. Simply put Extreme lift, Looks OK drive shaft angle doesn't mean it is OK. Pull the rear drive shaft and run it in 4 wheel. Bet that is the culprit.

 

[Hank]

Already pulled the rearshaft and ran on the front. Read the whole post damn it! LOL

Spent a few hours on the cruiser last night during the monsoon. We took out the brand new Precision universal joints. As I read here on good ol 'mud THEY ARE JUNK! I put in some GMB joints which are way heavier duty and work great. 1/2 problem solved. I then put in 4 degree shims to tip my pinion down. 85% vibes gone. I can now drive the Cruiser tolerably down the road but it still isn't right. I have a shudder when starting from a stop still. More shim will put the driveshaft past tolerable angles. I am going to deal with it as is for a while since I need the Cruiser for a couple up coming weekend and it does 70mph with little problem. In the near future I'm going to turn the shims around and maybe go to 6 degrees and get a CV shaft made. That should handle the issue for good. I'm disapointed that it comes down to that after being told by the manufacturer that zero shims would be needed, no driveline mods would be needed and I would net 100mm give or take over stock. I was also told to not worry about the sway bars (as stated above my rear has been off quite some time) but the front is needed for interstate driving. None of those dreams came true.

The good news is the Cruiser is sitting on a set of borrowed 35" BFG MT's on 15x10 Chrome mods with 3.75" Backspacing and it clears them quite well. I don't have the gear for them, it needs 4.88's something fierce. It sure looks good though. Nothing rubs, I haven't flexed it out to test yet but I don't think they will hit anything. I don't have pictures yet (MONSOON remember?!) but I will post up soon.

The other good news is I got the ride I wanted. It handles beat up streets and bumper interstate like a DREAM. I'm not sure yet that the velvet ride I'm getting is worth all the other headaches in the middle of wheeling season but I'd bet I'll be convinced after the first trail ride. I am running BDS 5500 series shocks at the moment which are not enough so the ride will only get better when I upgrade to some 9500 series or Bilsteins or KYB's if I can find them to fit. I'm also going to hook the front sway bar back up to be a bit more stable on the highway.

I'm 88% there and have to spend some money now. Thanks for all the ideas. Sorry I put so much faith in the manufacturer's advice.

Next question. Any other Toyota's with CV shafts that might bolt up? Thanks 'mud!

 

[Bryan062087]

It looks like you have pretty large oversize shackles installed. You could go back down to a stock size shackle if you want less lift and this could reduce some of your vibes.

 

[Hank]

The anti-inversion shackles that came with the kit are a bit longer than stock. The springs are also longer than stock. They were matched to provide optimum ride and therefore shackle angle. The ride is top notch and that of course means the angles are good. If I put shorter shackles on the truck I will not have correct angles and may lose the ride. I am not willing to compromise on the ride at all. A better ride was 100% of the reason for changing the springs in the first place. Snapping a spring eye off just rushed the situation. I understand your thinking and you are right, it would lower the truck and reduce the angle but it wouldn't get me to my end goal.

 

[calphi27]

I have been following this thread for a while and don't recall reading this: What kind of parabolics did you go with? The fire sale ones from MAF? How about some pics when you get it figured out. Thanks Hank!

 

[GLTHFJ60]

I have been following this thread for a while and don't recall reading this: What kind of parabolics did you go with? The fire sale ones from MAF? How about some pics when you get it figured out. Thanks Hank!

I would also like to find out so I can buy a set!!

 

[Hank]

This is a Heystee Suspension. HST Parabolic Suspension Systems

I installed from their kit:
2 leaf front springs
Anti-inversion shackles front and rear
2.5 leaf rear leaf springs (front of pack has three, rear has two)


Additionally I have installed:
BDS Shocks front and rear, these will be replaced soon with a gas charged shock with more length although they do ride quite well.
4 degree shims in the rear end
New universal joints in both shafts (rear twice!)

Quickly upcoming due to the lift:
Steering stabilizer (not replaced since I replaced all my wearable steering joints, not needed with stock steering geometry. Now needed due to increased bumpsteer from steeper drag link angle)
All four shocks
I will remove the 4 degree shims and install one the other direction to point the pinion at the t-case output to prepare for a Dual Cardan shaft to eliminate the vibrations hopefully for good.
Extended brake lines front and rear.
I tied up my LSPV and got my rear brakes back which is very nice. I might do the work to make the LSPV work again, might not.

 

[GLTHFJ60]

On their website, it says that this lift is only 50 to 80mm, which is no more than 3 inches! How high is your truck in real life? Measurements at the wheel wells??

I didn't think that a 3" lift created problems like this, but I have a feeling that this is more than 3".

 

[Hank]

These springs were intended to provide 100mm of lift: From Paul's email;
The lift was intended to be +100 mm or 4" so I guess I am close if your original springs where badly sagged. To get this kind of lift I lengthened the spring leaves so that the axle and shackles will remain in the proper positions, hence the need for lowering the axle buffers, otherwise you might get into trouble, geometrically speaking, under extreme loads or articulation.

I can't imagine doing any of this except the universal joints with a 3" lift. I have a brand new BDS that I was intending to put in when this lift entered the picture. (For sale!) and it is tempting to switch every time I battle this vibration. I'm getting rather used to the 35's on it though.

I'll measure it wheel wells down tonight. I don't have time right now. As the pictures show I was sagged enough for 33x9.5's to rub under articulation and now 35's on 15x10's don't rub under the same articulation (actually more, the front sway bar isn't there to limit things. )

 

[woody]

actually, I don't believe these specific springs are available on their website just yet

 

[GLTHFJ60]

actually, I don't believe these specific springs are available on their website just yet

Must be. I would love to get a set of these 100mm springs!

 

[Kurtis]

Did you get the vibes worked out? Sounds like these give a pretty good ride. What kind of flex are they giving you?

 

[Hank]

The ride is fantastic. The vibrations are not sorted out yet. I haven't had much time to work on the truck for a few weeks. I did put in new universals on the front shaft yesterday which won't fix anything vibrations wise but this time I put in the GMB brand. I'm going to run it a few hundred miles this coming weekend. I shouldn't but I don't have much choice. My next step is building a dual cardan type 1310 shaft and adapting that to the 'yota flanges I think. I'll update when I get more time and progress.