T&D FAQ

One answer to a question nearly everyone asks is, yes, even though T&D shaft-mount rocker arms are almost always “bolt-on,” the proper roller tip to valve relationship is critical. A little time and effort during assembly will reap huge benefits. In most cases, included shims will be adequate to reach proper alignment. T&D also builds custom height stands – many variations are on the shelf for immediate delivery. In extreme cases, machining the mounting pads on the cylinder head may be necessary. Never under any circumstances machine the mounting stands, grind reliefs into the rocker bodies, or modify the stands or rockers in any other ways.
 
Each rocker assembly is shipped with an instruction sheet that details just how to achieve optimum interaction between the roller tip of the rocker arm and the valve stem. We suggest that you familiarize yourself with that instruction sheet. If you cannot understand the basic instructions, please call or email our technical department.
 
Do you have special tools to help find this perfect geometry?

In every T&D rocker set is a small tool called a Stand Height Gage. When used per instructions, the stand height gage is invaluable for getting your rocker arms into their proper configuration. T&D also has available Pushrod Length Checkers. After the rockers are placed properly, you’ll need an accurate measurement to enable you to order correct length pushrods.
 
And, T&D also offers specialized tools to make your job of maintaining your valvetrain a breeze.
 
How do I determine correct pushrod length?

Once again, the instruction sheet is your best friend, so refer to it often.
 
Place the pushrod length checker into a lifter and install a rocker arm assembly. Be sure the cam is rotated to the base circle. Seat the bottom of the adjuster screw up against the recess in the rocker arm and turn the adjuster screw clockwise one full turn down. This is the initial adjuster position. Adjust the pushrod length checker tool to the proper length, remove from the engine, and measure its overall length.
 
It says that T&D rockers have internal oiling. What makes that different or better?

Yes, most T&D rocker bodies (except SportComp) have oil passages that enable engine oil to constantly pressurize the trunion bearings and the rocker tips. This feature gives a longevity factor to T&D rockers that the competition does not provide. It also cools the bearings and shafts. There is also an orifice in the adjuster screw that maintains oil to the interface between adjuster cup and pushrod end. This part of the oil passage must remain open and precautions must be taken to maintain adjuster position (another reason that pushrod length is critical).
The rocker arm should not be operated with the adjuster screw more than one turn up or down, from the initial adjuster position. Doing so will cut off the flow of oil to the rocker arm.
 
What is that adjuster specification?

We never recommend turning the adjuster more than 2-1/2 turns down. Pushrod length is determined by the following: (1) Turn the adjuster all the way up into the recess in the rocker body until it stops. (2) Turn the adjuster down one full rotation. (3) This is the initial adjuster position. (4) Once the engine is fully assembled, this will be the starting position where lash will be set, and the adjuster should NEVER be turned one full turn either up or down. For general information, the hole in the adjuster that feeds oil to the pushrod cup shuts off flow completely when the adjuster goes just past two turns down from the initial adjuster position.
 
Once I get the proper pushrod length, where do I get a set of good pushrods?

T&D Machine Products recommends that you choose the highest quality pushrods available for every application, and several manufacturers can provide them.
 
How much shim can I use under the stand to get my geometry correct?

Included in most rocker sets is 0.090” of shim. That is the maximum we recommend. T&D offers custom stands with extra height starting with +0.100” so it is very simple to get more height if necessary.
 
I threw away or I’ve lost my instructions, what do I do now?

Most of the basic instruction sheets can be found on this website. There may not be one for your exact assembly or part number, but similar engine types can use a generic instruction sheet (i.e. most big block Chevys assemble exactly the same). If the one you need for your particular application cannot be found here, please contact our technical department and one will be provided.
 
I lost some hold down hardware…

Every effort is made to include all necessary components for each rocker arm set. But, you might lose an adjuster nut or hold down stud under the bench. We’re happy to help you get your assembly back up to 100%. Just contact our technical department.
 
What are the proper torque specs for … ?

Please check the instruction sheet for your particular application for the torque specifications. There is a generalized torque spec chart on the website.
 
I bought a set of T&D rockers used off eBay…

Unfortunately, we don’t recommend this practice. At first, you are sure to think that we just want to make more money and want you to buy a new set but that is not the case. Weekly, we hear sob stories of people that buy what looks like a really good deal on the surface, but by the time the rockers are adapted to their combination they have invested more time and money than if they’d purchased a new set that is designed to fit their cylinder head and application. Just because the rockers are for a small block Chevy/Ford/Dodge, does not mean they are harmonious with every configuration.
 
Plus, there is absolutely no way to tell just how used or abused a set of rockers is. Ask yourself, would I buy a set of used aluminum connecting rods? Same material, same answer. No.
 
Often, we hear from a guy who has gotten a real deal on a set of rocker arms from a NASCAR “cup” team – often in the range of $250. And, we’ll tell you the truth, those rockers are the finest money could buy when the set was designed, machined and shipped. But, they are also quite proprietary so they need the cylinder head that went underneath them. We’re sure that a good engine builder can figure out a piston and pushrod length to match up a “cup” head and rocker set to a compatible block. But just a warning, it might not be the easiest process for a novice.
 
So, while some components can be purchased used in the on-line swap meet of your choice, we don’t recommend this practice for T&D rockers arms.
 
Are T&D rocker arms rebuildable?

Yes, certainly.
 
T&D has a free inspection process. You pay freight roundtrip. We take everything apart, then inspect, measure and advise. After millions of cycles, aluminum goes beyond its useful life.
 
In the case of your rockers, they may only need to have a few bearings replaced. But, they may need to be rebodied, while using the old bearings, axles, tips, etc. It all depends on their use, abuse, age, etc. Or, possibly you over-revved and put a valve into a piston. It is possible that just one or two rocker bodies might need to be replaced.
 
If you suspect anything, even the age of your rocker system, return them for a full inspection. It is best to let the sales department know that your rockers are headed this way but not a requirement. Make sure to enclose pertinent information and just what you want done. Again, it is a free service from T&D.


Will you build me a custom set of rockers for my oddball engine?

Actually, virtually every set that goes out the door is a custom set, given the many options for ratios and offsets available. However, we also offer customers full engineering to design and build rocker arms to fit a wide variety of configurations. We cannot say an immediate “Yes” to every request due to the heavy load in engineering, nor can we say, “If its got rocker arms we can build them.” But, given time, we have built rocker arms for some pretty obscure engines, including Ardun, Desoto, Lycoming and Polaris.
 
Can I buy direct from T&D?

Yes, certainly. Call us at (775) 884-2292. However, it is possible that one of our many T&D Dealers worldwide can provide faster service and even a slightly better price.