TR4/4A TR4 or TR3 Tranny?

[CJD]

Today I responded to an add on Craig's list for a TR4 tranny. The price was right, so I went to check it out...

Two hours later I left with 3 trannys, 2 high port heads, 8 distributors, connecting rods and used pistons for at least 6 TR's, 4 high port manifolds, 4 SU carbs...and the list goes on. Two of the trannys are disassembled and obviously TR3's with no synchros on 1st gear.

But my question is, is there a way to tell if a tranny has a 1st gear synchro without disassembling it? Now that I have it home, I am wondering whether the "TR4" tranny I got was really a 4 or not...

 

[TR3driver]

The 4-synchro gearbox (TR3B through TR6) has a larger cylindrical bulge that extends only partway on the LH side, which you can see in the lower RH corner of this photo

(That is actually a later TR6 box, the TR4 version has the same bulge but lacks some of the stiffening ribs and the flange isn't as beefy)

The 3-synchro gearbox (TR2 through TR3A) has a flat raised area instead

 

[CJD]

Thanks Randall! I was hoping it was as easy as that.

The gentleman I got the parts from was helping a widow sell her husbands 12 car collection. The interesting part was that he said it was obvious that out of all the Healys and Jags, the TR4 was very obviously the car he liked and worked on the most!

Don't know what I'm going to do with all this stuff...but sure it will come handy at some point for me, or the next enthusiast...

 

[KVH]

I forget: What is a high port head?

Also, I see ones all rusted and poorly kept. How is a head properly stored? Oiled and wrapped in heavy plastic? Is there a process for proper storage?

 

[TR3driver]

"Low port" heads were only on TR2 and very early TR3; the high port head was introduced at about the same time as front disc brakes. There are outlines at https://www.tr3a.info/FAQ_heads.htm

I've been experimenting with the best way to store components like cylinder heads. The army used to use a coating known as "cosmoline" that was extremely effective; but the spray can of "Cosmolene" that I bought did not work nearly as well. The original would form a thick, hard, dry wax coating over the outside, with a layer of oil next to the metal. The stuff I got appeared to just be the oily part, no wax, and the oil eventually washes/runs off. Apparently Cosmolene is now a brand name with several products available, so likely I just didn't get the right one.

So far, the best I've found is https://www.blastercorporation.com/Corrosion_Stop.html It goes on fairly thin, to penetrate into small openings and existing light rust; then dries to a fairly heavy grease-like film. The main downside is that the grease remains sticky and so accumulates dirt and gets your hands dirty if you have to handle the part. But it appears to have stopped the corrosion entirely on the Herald gearbox stored outdoors (actually in the scrap pile, waiting to get hauled to the dump).

 

[CJD]

My usual rust prevention is LPS3. It makes a waxy coating, but will still collect dirt.

I find the real key is keeping the moisture down. I grew up in New Orleans, and everything made of bare steel rusted overnight, just from humidity in the air. Here in Ft Worth, the humidity is normally 40% or less, and I can sand blast iron and leave it unpainted for months without getting any surface rust at all.