12HT vs. 2H rocker arms

[shaun05]

Hi guys/gals

I'm just wondering if anyone knows what the difference between 12HT and 2H rocker arms is? I'd like to get a new set of arms for my 12HT but unfortunately, the people at Toyota and the aftermarket diesel engine supplies places I've been to, tell me they are unable to get them. They can get 2H arms, but not 12HT.

The Toyota part numbers are different.

12HT arm is 13811-68020 and 2H arm is 13811-68011

If anyone has any thoughts on the matter, please advise. Perhaps if you have both 12HT and 2H arms in your posession, you could take a look and see if there is any difference.

Cheers,
Shaun

 

[shaun05]

Really? No one has any idea?

 

[Garry]

I know the heads are different between the 2H and the 12HT. The rockers may be different too.

 

[ZD460]

Can get from both these sites
Toyota 13811-68020 (1381168020): Buy genuine car parts - Amayama

13811-68020 TOYOTA New parts search — IMPEX JAPAN

 

[shaun05]

Can get from both these sites
Toyota 13811-68020 (1381168020): Buy genuine car parts - Amayama

13811-68020 TOYOTA New parts search — IMPEX JAPAN

Thanks for that ZD460. Much appreciated.

Have you actually used either of those suppliers? Just trying to make sure they're reputable before throwing $250 at them.

Cheers,
Shaun

 

[Locked79]

Thanks for that ZD460. Much appreciated.

Have you actually used either of those suppliers? Just trying to make sure they're reputable before throwing $250 at them.

Cheers,
Shaun

I can vouch for Amayama, have spent thousands $$$$ through them, never a problem. Always correct and on time.

 

[Davaa]

I have inspected both rockers but not side by side. Visually they looked very similar.

 

[ZD460]

Hi Shaun I used both and haven't had a problem.

 

[shaun05]

The camshaft is discontinued.

This number is for the rocker arms. The camshaft is a different number.

Thanks very much for all of your replies guys. I'll see if I can get an order through and see what happens.

Cheers,
Shaun

 

[OGBeno]

This number is for the rocker arms. The camshaft is a different number.

Thanks very much for all of your replies guys. I'll see if I can get an order through and see what happens.

Cheers,
Shaun

D'oh!! My bad. Late night misread.

Thanks!

 

[shaun05]

D'oh!! My bad. Late night misread.

Thanks!

Well, it didn't make a difference anyway. I put the order through but got an email back in the morning saying the order was cancelled, because the parts are no longer available.

Looks like it's back to the original plan of using @H arms, if I can confirm compatibility.

Cheers,
Shaun

 

[Redbj40]

Was there a conclusion if 2h arms would be OK on a 12ht?.

 

[Davo]

Hi, I just bought a new 2h rocker arm and did a bit of a comparison with my 12ht rocker arms…. The first set of 12ht rocker arms (I’ll call set A) were very similar, but slightly different.….

In the first photo, is a row of 12ht rocker arms (engine set A), 2nd from right is the 2H rocker (part number above) and furtherest on the right is another 12ht rocker (set B) off another 12ht engine that I am building.

As you can see, there is a small variation in all of set A 12ht, with the 2h being the same length as the smallest of that set A.
The oil holes are similar in size but, the 2h top hole is in a slightly different position (doesn’t look like it would be any different in effectiveness). Oil holes look to be 3mm diameter.

The other 12ht rocker arm (set B) is a lot smaller in length and also has a oil hole position like the 2h rocker, but the top hole is 4mm in diameter.

On the paper you can see the 2h has slightly more offset from the right compared to both set A & B rockers.

The set A rockers are all slightly thicker in the valve contact tip compared to the 2h rocker and are all slightly “heavier” in the rib area.

Above is rocker from my set A, put on the head/rocker shaft of 12ht set B. Note Rocker tip to valve tip.

Above is the 2h rocker arm on the same set B 12ht head

Above is the shorter, original rocker arm back in its position on set B head/engine

 

[Davo]

rocker off set B & it’s contact wear mark

Above, from left,12ht rocker from set B (push rod end of rocker on a block of timber, for height comparison), 2h rocker, set A 12ht rockers (showing thicker contact tips).
Both pedestals from engine/set A and B look the same.
Maybe there is a difference between block/heads in the 12ht’s over the years or maybe rockers were made at different foundries??

All of the rockers from my B set have different numbers in them (14, 12, 12, 21 etc…), no numbers on the set A rockers and 162 on the 2h rocker
Hope this helps answer the question…..2h rocker may work depending on valve tip contact. If I get time I might remove the valve springs, open up the valve a bit and compare how the three types of rockers make contact….

unfortunately I finished my rocker lash maintenance 2 weeks ago on my daily driver 12ht hj61, it would have been interesting to compare it’s rocker arms to the set A, B & 2h. Next time…..

 

[duncanrm]

unfortunately I finished my rocker lash maintenance 2 weeks ago on my daily driver 12ht hj61, it would have been interesting to compare it’s rocker arms to the set A, B & 2h. Next time…..

Superb information and photos!