4-speed rebuild. Tips please!

db · Post by db » Fri Nov 09, 12 6:23 pm

It's jammed in 2nd a couple of times before and it's done it again today. I previously ran it with ATF for a bit to Bananarama! and now it's on decent 80/90 so it's got no excuses!
I'm fairly confident from what I've read that I can do the rebuild, but any help will be much appreciated.
Should I think about doing any upgrades while I'm in there?
Has anyone bought a rebuild kit? Where from/ how much/ is there a UK supplier?
Weirdly I'm looking forward to this, I've never had a manual box apart before

Pete · Post by **Pete** » Fri Nov 09, 12 6:44 pm

Shifter and rod adjustment.

There is normally a shaped tool you insert into the shifter that indexes them and you then set the rod lengths accordingly.

Alex Doing and I made one and set up the AAR that way.

Alternatively, do the sensible thing and install a A727

Adrian Worman · Post by **Adrian Worman** » Fri Nov 09, 12 6:57 pm

Give mick70rr a shout Paul, he did his a few months back.
It's pretty straight forward to do, you'll enjoy it mate.
Internally there ain't a huge amount to modify but you can order improved hubs and stronger forks from Brewers.
Get the rebuild kit from them anyway Paul, pretty good quality.

I don't understand what Pete means........... the only 727 you see should have Boeing stamped all over it

db · Post by db » Fri Nov 09, 12 7:29 pm

I've been through the rods etc the previous times it's seized Pete, I took the rods off and found the shaft into the box wouldn't budge. I worked it with a big adjustable and managed to free it. After speaking to Ade last time we decided the synch cone must be a bit knackered (I did stupidly drive it at the start with no oil

) I hoped it would sort itself out but apparently not...

I've not investigated it today but it'll be the same.

Adrian Worman · Post by **Adrian Worman** » Fri Nov 09, 12 7:36 pm

There's a good chance that you can clean up the seized/damaged synchro hub and rings with an engineers stone, I've done it before and saved a synchro by doing that.

terryr · Post by **terryr** » Fri Nov 09, 12 7:41 pm

when it was working did it change down ok ,i had a box in the demon with no syncros and that didnt jam up ,i think petes right in saying its adjustment,i used to have a bit of aggro with my 4 speed ,but i put on rods that had rose joints on them ,where did you get the box

Mick70RR · Post by **Mick70RR** » Fri Nov 09, 12 7:41 pm

Brewers sell a rebuild kit for around $100, sycro rings are extra if you need them. It's a pretty easy job rebuilding these box's, I don't think you'll have a problem. You will have to make a dummy cluster shaft to hold the cluster shaft bearings and thrust washers in place when you assemble it. I turned a length of delrin down but I've heard of people using a piece of broom handle.
Might be best to strip it down before you order parts in case there's anything else you need.

shovelheadrob · Post by **shovelheadrob** » Fri Nov 09, 12 8:47 pm

terryr wrote:when it was working did it change down ok ,i had a box in the demon with no syncros and that didnt jam up ,i think petes right in saying its adjustment,i used to have a bit of aggro with my 4 speed ,but i put on rods that had rose joints on them ,where did you get the box

The box you got with the Demon had a proper slickshift conversion, with special sliders & I think no synchros, I know when I drove the car it came from (now Tony's Satellite you could powershift it using the clutch, or just lift the throttle & bang another gear (no clutch), downshifting however required a bit of nifty footwork!
When I had the GTS that locked up a couple of times, due to shifter rod mis-adjustment, sorted that out & it was a joy to drive, even with a V-gate shifter.

db · Post by db » Fri Nov 09, 12 8:55 pm

Thanks Ade, fingers crossed! Not sure when I'll drop it out but we'll see what we find!
Terry- the box is an 18 spline, came from Dunc.
I'm almost certain it's NOT adjustment- with the rods removed I put a big adjustable over the shift plate on the end of the 1-2 shaft into the box and it wouldn't move. I worked it back and forth for a few minutes, then it came free. I've not done that this time yet but it went exactly the same way.

terryr · Post by **terryr** » Sat Nov 10, 12 5:27 am

The box you got with the Demon had a proper slickshift conversion, with special sliders & I think no synchros, I know when I drove the car it came from (now Tony's Satellite you could powershift it using the clutch, or just lift the throttle & bang another gear (no clutch), downshifting however required a bit of nifty footwork!
When I had the GTS that locked up a couple of times, due to shifter rod mis-adjustment, sorted that out & it was a joy to drive, even with a V-gate shifter.[/quote]

it may have been a trick box,but the wife couldnt get the hang of it

it was like driving a 1973 erf truck ,you had to double the clutch to change down and have the revs right to change up ,i swapped it out for another ,which was a really good box and thought it may be the one in dbs car ,but its not as that wasnt an 18 spline

ive got some stuff in boxes brand new i got with my old demon ,ill get some photos or rob will know what they are ,think they are sync drums

shovelheadrob · Post by **shovelheadrob** » Sat Nov 10, 12 7:57 am

If it's the bits I think, they are some of the parts required to change to a slick shift, as you said Terry, it ain't for girlies!!

terryr · Post by **terryr** » Sun Nov 11, 12 11:48 am

yep i got it ,,but slippery didnt,,,6000 and whack it in,,,,no not for pussay funny tho

Six-pack Speedshop · Post by **Six-pack Speedshop** » Thu Nov 15, 12 6:18 pm

We had a client with this problem too (finally it wasn't me having 4-speed for once lol) and without the shifter rods attached it still didn't want to do anything. After opening up the box the problem was on the inside of the gearbox side cover, the rod assy between the 2 shifter pivots we're jammed (probably because bad adjustments in the past) so it was almost in multiple gears. Was a simple fix.

But if it's more then that there is no rocket science inside a 4-speed so just give it a go. Just let me know what you find as I have a partial rebuilt kit myself (haven't synchro's in mine so they're still there) which might contain the parts you need.

db · Post by db » Fri Nov 16, 12 1:14 pm

I took off the side cover last night and it's just as Hans says- it had's fully disengaged from 3rd when it went into 2nd so the levers got stuck. There's no seizure in the gears themselves.
Looks like you guys were right, down to poor adjustment. In my defence I did it properly with the rod through the shift levers, I'll double-double check it next time!

I'm still going to do a full stripdown as the front bearing has a lot of play, it has a few leaks, and I'd like the peace of mind to know it's all cool in there.

Hans- I'll check with you before I buy anything

I'm doing a write-up of this in my workshop thread.

Dave-R · Post by **Dave-R** » Fri Nov 16, 12 1:27 pm

Six-pack Speedshop wrote:We had a client with this problem too (finally it wasn't me having 4-speed for once lol)

Is that you Hans?

Told you that you would eventually get around to using an automatic.

Good to see you are doing OK.