Synchro Hub Alignment?

[S2Jay]

Hello to everyone!

When I dismantled the Tranny, the synchro Hub was flush with the splines on the Mainshaft, The old synchro was removed & the new one put in its place, but on reassembly there is a significant step or gap between the end of the Hub & the splines, as shown in the pic. This has been re-assembled twice now, once by a shop with a proper press.

The gear & new synchro ring spin freely, and it is possible to slide the gear back & forth on the shaft about the same amount as this added gap dimension.

I must be doing something incorrectly, or not doing something necessary. Has anyone any thoughts on how this could occur? Any ideas on why it will not seat all the way back down, or how to correct this?

Or is this an insignificant issue that will allow further assembly & not create a problem in operation?

Any thoughts / suggestions / recommendations welcomed.

Confused in California
Jay
26 / 5009
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[garyeanderson]

Are the synchro rings the correct ones? Late synchro rings will not fit inside early Synchro ring hubs. A side photo may help, please disassemble and take more photos of the parts. I'll see what I can find when it gets light.

Gary

So I found the synchro hubs. On the left is an Early hub and on the right is the Late hub

Picture 1 Hubs with rings.

Picture 2 Hubs with the rings flipped .

Picture 3 Hubs with the rings flipped and early and late synchro rings swapped.

Picture 4 Hubs early and late with the rings in standard position and synchro rings swapped.

Picture 5 Rings in front of there respective hubs.

This is one of the photos I use on re-assembly, it is from the 1967 Cortina mk2 W.S. manual.

Get Dave Beans Elan Catalog and read the gearbox section. There are 3 versions of this box and I don't think that the differences are noted except the Bean catalog. The S1 workshop manual is also very good to have.

[S2Jay]

Gary,

Thanks for the pics.

The new Synchro Rings are the reproduction items made by/for RD Ent. and come in a set of all 4 Rings. They were marked with the 2 different P.N. used for the 1st/2nd rings vs. the 3rd/4th. I compared the new ones to the old ones being removed to be sure that they looked and measured as a match and were numbered correctly for their respective placements.

Attached are [I hope] probably better pics of [1.] the step gap where the Hub is not seating all the way down onto the Mainshaft, [2.] the Synchro Ring from the side, showing it positioned up against the Hub, and [3.] the Hub / Synchro assembly again from the side showing that the Synchro Ring can be moved back away from the Hub. [I could not figure out how to stack all of the pics together in one shot as you have.]

The closest I can measure suggests that the Hub is about 0.040? from being flush with the end of the splines on the Mainshaft [as it was when it was removed from the transmission], and that the gap between the Hub and Synchro ring is about 0.057? at its largest.

Confounded in Cal
Jay
26 / 5009

[garyeanderson]

Hi Jay

Original Gear and Synchro hub? Right! and just new Synchro rings for the Ultra close box? Right!

there are 3 possible gears 21 wide - 23 semi-close and 24 for the Ultra close but I don't think it matters which. this Gear is slid on the shaft and is just sub-flush so there is not interference with the Synchro hub.

There are two Synchro hubs, one for early and one for the late synchro rings. The chances of something not stacking up is low. I grabbed some parts and "tossed" them together, the only thing I didn't do was put on the C ring but it does slide into the groove. The gear and hub just dropped into place without any pressure other than gravity. I remember using a press to disassemble at some point but its been a couple years since I played with boxes.


Maybe time to measure the Synchro hub height, I disassembled the hub and measured .700 inch for the height.

Gearbox pages from August 1966 Cortina workshop manual below