3B Rocker Arm Variants, Help Needed

[Chris Wilcox]

Hi,
In refreshing a 3B head gasket we ran into something that is puzzling. Well first off the rockers on the existing engine have up to 0.058" of wear at the valve so the valve stem has "pocketed" into the rocker surface. We have another couple 3B's, one running, one not, to rob parts from.

The worn rockers have a full ball end for the pushrod that measures 8mm diameter. The adjuster thread is 10mm.

The spare rockers have a 6mm diameter pin end on the adjuster with a spherical tip which may or may not be 8mm diameter, it is hard to tell. The adjuster thread on this set is 8mm.

We were planning to simply swap rocker assemblies from one engine to the other when the wear was identified but now are not sure what to do.

Does anyone here know the background on the differences observed and if the parts are interchangeable?

See the build thread here for intercooler install if interested:
https://forum.ih8mud.com/diesel-tech-24-volts-systems/727966-intercooler-3b-turbo-project.html

Thanks,
Chris

 

[magnus_heydoc]

no one?

67 views and no comments?
has nobody ever run into this before doing a rebuild or head re-freshening?
I'm pretty curious myself.
aaron

 

[roma042987]

sorry cant be of any help but i will add that some late model 3b's and i believe all 3bII's have aluminum rockers. I cant confirm this but was told so by a reputable source.

 

[Chris Wilcox]

Neither of these are aluminum. One rocker adjuster is an 8mm OD sphere where it contacts the pushrod. The other is a 6mm dia cylinder with a curved tip. We have several of each type but nothing else that seems to be significantly different to pinpoint the difference. Anybody running 3B's anymore?

 

[Dieseler]

Got any pics of the different push rods and rockers.
Are these 3Bs all form the same year or are they 81 and 85 production dates which would probably explain differences in sizes since they made improvement changes over the years with the 3B.

 

[Turdzoplenty]

Diseler is right. somewhere in 82 83 84 the rockers and pushrods changed. what ever year they went to the 5 cam bearing setup is the year.
toyotadiy. just check production dates.

 

[magnus_heydoc]

Well someone's information is not accurate.........
Dan at 4wheel tells me there were no 40 series that had the 5 cam yet I have a 40 series with the bigger rockers and rods.

 

[flop]

you must have a 60 transplant

 

[magnus_heydoc]

No sir, I know the history of that rig. It's an 84 42 through and through.

 

[amaurer]

Bearings, arms, lifter rods, and adjuster screws all changed in 08/1984. A 1984 model BJ42 should have a 1983 production date, so this is a bit strange if its the original motor in your BJ42.

If you tell use your VIN/serial number we can tell your production date and be sure.

 

[Chris Wilcox]

Regardless of what the VIN indicates you have the 8mm ball end rockers plus several serviceable sets of the smaller type. How many parts would have to be changed to swap the smaller type into this engine:
1. Just the rocker assembly? ie the pushrods will fit the rocker properly.
2. Rocker assembly and pushrods. ie the cam followers are the same for all model years.
3. Rocker assembly/pushrods/cam followers must be changed as a set. ie nothing is interchangeable between the model year changes for the valve train.

Any help is appreciated. We put lots of work into his truck recently and do not want to damage anything. If all else fails we will do a thorough inspection and make the call but good experience is always highly valued.
Thanks so far.

 

[amaurer]

Cam, lifters, pushrods, adjusting screws, and rocker arms are all different between the two versions.

The difference in the cam is primarily the addition of the 2 extra bearings so that certainly can't be transferred. I'd be hesitant to mix cam/lifter/pushrod combos without some very careful measuring.

 

[amaurer]

I would also add - many of us, myself included, have ground divots out of rockers that are damaged like yours are. Its simple, effective, and in my experience, permanent.

 

[magnus_heydoc]

Apparently Super Grover has a big set to me in the mail today so it'll be back together in a few days. Thanks for the help.

The whole drivetrain came from 1984 42 series if I recall. The cast number on the block is 11411-58030.
I'm really curious of the pattern of change.

 

[amaurer]

Apparently Super Grover has a big set to me in the mail today so it'll be back together in a few days. Thanks for the help.

The whole drivetrain came from 1984 42 series if I recall. The cast number on the block is 11411-58030.
I'm really curious of the pattern of change.

That settles it then, your 3B was definitely not from a 40-series.

Late model North American 40/42's got either:

11400	BLOCK ASSY, SHORT
11400-58012	 (09/1982 - 07/1984)
11400-58040	 (08/1984 - 09/1984)

In other words, not your block.

Doing a reverse search your block number, 11411-58030, shows it was never used in a 40, in any part of the world:

Market	Date range	Model	Frames/Options	Found in diagram
Japan	09/1984-07/1987	TOYOTA DYNA, TOYOACE	BU6*,7*,8*,9*	11-02: SHORT BLOCK ASSEMBLY
Japan	08/1987-07/1988	TOYOTA DYNA, TOYOACE	BU6*,7*,8*,9*	11-02: SHORT BLOCK ASSEMBLY
Japan	11/1984-12/1989	TOYOTA LAND CRUISER	LJ71,BJ7*	11-02: SHORT BLOCK ASSEMBLY
General	11/1984-12/1989	TOYOTA LAND CRUISER	RJ70,LJ70,BJ7*,HJ75,FJ7*	11-02: SHORT BLOCK ASSEMBLY
Europe	11/1984-12/1989	TOYOTA LAND CRUISER	RJ7*,LJ7*,BJ7*	11-02: SHORT BLOCK ASSEMBLY

Note theres not a single north american application - that block was imported in a 70 or dyna from overseas and swapped.

 

[magnus_heydoc]

block serial number 0627365.
The guy I got that drivetrain from did own a white CDN spec. 70 series. Maybe it went in there?
Hey thanks for searching around. Clearly I was misled. Interesting.

This 3B I own has a big rocker arm assembly as well: 0451989
This 3B I own has a small rocker arm assembly: 0641510
Any idea of the vintages?
Where do you find your vintage info?

 

[amaurer]

block serial number 0627365.
The guy I got that drivetrain from did own a white CDN spec. 70 series. Maybe it went in there?
Hey thanks for searching around. Clearly I was misled. Interesting.

This 3B I own has a big rocker arm assembly as well: 0451989
This 3B I own has a small rocker arm assembly: 0641510
Any idea of the vintages?
Where do you find your vintage info?

All CDN spec trucks used 11400-58040 blocks, the 11400-58030 block is definitely imported. Its a real mystery.

Toyodiy.com is what I use - it will tell you production date based on frame serial number, but can't look up anything based on part-specific serial numbers, only part numbers.

As far as I know there is no way to determine build date from engine serial number... yet. I see you found, and posted in, Lostmarble's thread of serial numbers: thats a grassroots effort to figure it out but there is no official source of info.

 

[magnus_heydoc]

There's virtually no chance that motor was imported. However, I was wrong in this thread already.
I know the PO very well so I'll call him. the only way it's imported is if someone other than him did it but it's highly unlikely. We had 70 series sold in Canada domestically. They were around so if someone wanted one 15 years ago they were reasonably accessible. however, stranger things have happened.
any way you can narrow down production dates from the serial numbers or do I need block castings as well?

 

[amaurer]

There's virtually no chance that motor was imported. However, I was wrong in this thread already.
I know the PO very well so I'll call him. the only way it's imported is if someone other than him did it but it's highly unlikely. We had 70 series sold in Canada domestically. They were around so if someone wanted one 15 years ago they were reasonably accessible. however, stranger things have happened.
any way you can narrow down production dates from the serial numbers or do I need block castings as well?

Wellll it looks like maybe its not so clear. The EPC may not be perfect in this area.

In the other thread I did some rough guessing and the 0627365 block serial is from around Nov. 1983 which is about right for a 1984 model truck. Its certainly too early to have come from a 70-series.

Also in the other thread, VTCDN posted that he has a 1984 model BJ60 (VIN JT3BJ60G5E0012405) with the 58030 part number like yours... the EPC "claims" that should be impossible for his truck as well, but there is a pattern here.

I would say theres a reasonable chance its not a swap after all.

 

[magnus_heydoc]

It's not fit any patterns that I could see from all the different sources I've consulted.
Super strange.