Thread: options to link a 186 to a more robust transmission

Seem to be plenty of Holden 6's in front of Series gearboxes without problems.
There has been mention of poor alignment of some adaptor plates causing problems but fitted correctly and driven sensibly the box seems to handle the Holden motor without issue.

Someone will be along soon with first hand experience.

Gearbox rebuild in my thread here Isuzu C240 powered Series 3
This was a straightforward strip, replace synchro springs and re-assemble (a few pictures have been removed unfortunately). I'm sure there are more detailed rebuild explanations out there....


Colin

A good LR gearbox is more that good enough behind a holden 6 - 40 years ago I had a Holden 6 in front of my series 1 86 which was my everyday driver at the time and doing the 700km round trip from Nowra to Newcastle and back every week for 6 years. The box was up to the job.

garry

G'day All,

It may not be all that bad. Common fault with the 2A gearbox is broken Syncro springs that can lockout 3rd and 4th gear. Usually they break and get shredded thru the 3rd/4th gear set. A quick way to check is remove the drain plug and oil to check for broken or shredded metal. You can remove the bellhousing to gain access to the Syncro hub that sits on the main shaft. Follow the manual procedure to disassemble.

Chris

There is the Cabstar 5 speed conversion that was done for the series - but they are quite rare now to find although I did sell a complete set up 6 months ago. As mentioned, the series box is fine for a Holden 6 as long as the alignment is correct and this is generally what chews the gearbox out.

There is now plenty of evidence that the Rover gearbox is perfectly capable of handling the output of the 186, and that gearbox failures are almost all the result of misalignment due to sloppy manufacture of adapters.

Aligning the engine and gearbox properly will be a lot less effort and cost than converting to a different gearbox.

Of course, the ideal situation would be to install the original type of engine, but this is also likely to be expensive.

The other issue with the Holden is that for highway driving, it really needs the overdrive as its rev range is different from the Rover engines. The Fairey overdrive is not particularly robust, and parts are hard to find and expensive when you do find them.

Parts to repair the Rover gearbox are available, and not particularly expensive, and with a manual, common sense, and a bit of mechanical nouse, anyone should be able to overhaul it. You need to know that gear ratio and other changes happened during the production history, and the box number or a good description of the parts is needed when ordering parts.

One concern is that you quote a S3 with a 2a box - the S3 and S2a box are definitely not the same, and while it is possible to swap them, the different clutch operation arrangement means it is a pretty big job, so you need to make sure this is what you have.

The Series 3 has the clutch slave cylinder on the left, and is all synchromesh, the 2a box (and S1 and S2) has it on the right and only has synchro on 3 and 4.

Originally Posted by Busted Syncro

G'day All,

It may not be all that bad. Common fault with the 2A gearbox is broken Syncro springs that can lockout 3rd and 4th gear. Usually they break and get shredded thru the 3rd/4th gear set. A quick way to check is remove the drain plug and oil to check for broken or shredded metal. You can remove the bellhousing to gain access to the Syncro hub that sits on the main shaft. Follow the manual procedure to disassemble.

Chris

thanks chris will pull the gearbox out and start the investigation

G'day all,

A very important bearing to check if the flat Syncro detent springs have been shredded is the needle roller bearing 06397 on the front of the mainshaft. Two types can be fitted, a hollow roller and a solid roller. Check very carefully for tiny cracks in the hollow rollers and damage to the cages. If not replaced they will fail!. As mentioned by others misalignment of the adapter on the Holden engine can damage the primary pinion bearing and housing on the gearbox.

Hope it's a simple fix!.
Chris

Originally Posted by JDNSW

There is now plenty of evidence that the Rover gearbox is perfectly capable of handling the output of the 186, and that gearbox failures are almost all the result of misalignment due to sloppy manufacture of adapters.

My Holden conversion was done without a conversion kit. The previous owner just got a cold chisel (not a drill) and punched holes through the LR adaptor plate that bolts up to back of the Lr 2 litre engine and bolted the Holden engine up through these holes. The bolts were always a little loose and allowed the engine to sort of bounce around to find the sweet spot and stay aligned - just like a loose distributor finds its sweet timing point where vibration is the least.

Actually, despite what it sounds like it, it worked and had no major issues and the PO saved on the cost of a conversion kit.

Garry