“… Based on my figures, if you want to change the ride height by X inches, you should rotate the TB by X/0.137 splines at both ends in the appropriate direction…”
Hi David,
The quote is taken from your post in 2015 and I’m about to adjust my LHS TB. I need to raise the car by about 1/2". Now this 1/2" required increase is measured from the lower A arm pivot point, to the ground and I believe this is the correct location from which to take said measurement for ride height.
My question to you is…where on the car did you measure the change in ride height derived by using the 0.137? Was it at the pivot point for the lower A arm to the ground or somewhere on the body to the ground?
I had to set my TBs 3 or 4 times before I got it right. IIRC the concept of adjusting the ride height by rotating them a certain number of splines is a fallacy. The splines, 24 at one end and 25 at the other, are there to act as a vernier for getting the rear TB bracket holes to line up with the holes in the reaction plate and the frame. This is after the TB setting link has been put in place between the shock mounting points. An adjustable link can be cobbled together using a big hardware store turnbuckle and is quite useful for making incremental changes.
Measuring front ride height is described in the manuals and involves a couple of measurements and some arithmetic. And most importantly, after a reset the car will settle so drive it about 100 miles to see where it ends up.
Less
Have you ever set the TB you might want to call me if you haven’t. I’ve played with mine a lot I made a setting link and gage they can be a real bear if you don’t know a few tricks
Cheers. Jim
I’ve never set up a long wheelbase car. I kind of thought they were adjustable?
On a short wheelbase you do it by removing tension and increasing the spread between the upper and lower shock mounts and then fixing the bar in the new position.
It would be more like a book but it’s on my list I’ve done a lot of it to the point where I can take my TB out with my fingers . thought I could help him quickly by talking should really make a video
Exactly
Only 3 or 4 times your good and forget what the manual says about how to do it if you want to stay out of the insane asylums
If the car has never been touched it’s probably the absolute worst job but it doesn’t have to be but
you will need more than a case of beer
Here’s the coles notes
Jack the car on stands at front place stand under lower a arm mount not interfering with movement
Jack rear 6 inches higher is better for both
If your car is untouched have a beer and get ready to get dirty I’m assuming the TB has not been off
Remove front wheels and bag the splines
Disconnect the front brake pipes at the flex line you need new brake fluid anyway
Disconnect tie rod
Remove the front axel carrier so the lower a arm can swing I just take it off easier with two people it’s heavy don’t let it neck around wreaks the gator flanges
Move to reaction plate and remove the 4 nuts holding the TB adjuster 9/16 the threads are probably mashed, the exhaust is probably in the way and so is the ground strap I remove them , after you fight it you will to
The bolts can be removed by moving the lower a arm to unload they slide out if not bent mashed Or deformed
Remove the long 1/8 TB retainer bolt in a arm ,careful it can hit the frame, 1/4 nut on it ,corrosion can be bad it just slides through with a nut on it in a perfect world don’t bend it on the frame moving the a arm
The TB is now ready to come out but is it rusted, how about the adjuster at the reaction plate
Get a long bar 5/8 3 ft long with a point on one end place it on the front of the TB it has a center dimple
Get to pieces of wood and clamp them to the rad mount with a hole to slide the bar through
It hold s the bar in place while you hit it with a big 5 lb hammer work up to it ,maybe your wife will hold the bar and you won’t need the wood block
The TB is not straight to the adjuster it’s slightly off ( old age, twist I don’t know but it is)it moves around as you rotate the a arm and pinches the splines find the neutral position, it comes off a lot easier this is why you take it all apart, you maybe able to leverage the adjuster off independent
I’ll take a picture of the set up ,my gage and adjuster ,…page two to come . I’ll talk about shock length, droop ,and tie rack rubber mounts getting torn along with re assembly
This part should keep you busy for a while. Cheers. Jim
For me a martini after a days work, maybe one or two brews while the job is in progress.
But yeah after one or two times it gets a lot easier. But don’t make the mistake I made and not let the car settle, that cost me one whole iteration as I was chasing my tail.
Yes, thanks Jim, and I’ve done this before. The car has been refurbed/restored extensively so all is clean and shiny. This job entails resetting the LHS bar and the note written by David Langley back in 2015 detailed what sounds like a decent theory of spline movement and resultant changes in ride height. I was hoping David could clarify a question about where his measurements were taken…seeing as I’d like to get this job done and dusted with just one more try…
Ah, okay so it will be established by adjusting the lower control arm span. Whether you’ll be able to accomplish it will depend on how open the unladen span currently is, and whether it can physically be dropped far enough to accommodate a half inch ride height change. My last pair had reached the max span of about 17" (accurate for a short wheelbase car) and the ride height was still insufficient. Thus they had to be replaced.
By David’s calc I believe I need to move mine about four splines. That point is also kind of moot right now because as I was lifting the car on my two post lift, one of the lift cylinders blew! Hydraulic fluid all over the floor but luckily none on the car!!
Now have to try and find parts for it. Then the fun begins again.
Les
I went with the wife for a coffee and to get pics of my set up but the roads are closed for floods and wind here sooo tomorrow. ( cars at my hanger) A car lift sounds luxurious I’m afraid to dedicate space for one
Having a warm dry well lite place is 90% and having the setting link really helps because it locks it all up while you fit the TB I wouldn’t do the job without them now easy to make to. going to sports therapy before the job helps to
Cheers. Sounds like you got this
I meant to mention that xks limited advertised an adjustable TB reaction tie plate years ago I’ve never seen one
The bars are actually bent under load. There is one position you can raise the lower control arm to (after disconnecting the rear arm from the frame) where the bend is minimal and it’s at that position you knock the bar out of the front suspension and also install it.
I guess I need someone to explain to me how you can adjust the ride height by rotating the torsion bars some number of splines and still get the bracket and bolt holes to line up. Front splines or rear splines? Is one end fixed?
