Escort Sigma 1600 Race Car

[Roadsport]

Re: Escort Sigma 1600 Race Car

Still waiting to get a chance to pick up the brake discs from the machine shop. Meanwhile I took a first glance at the SL72. Still pretty clueless but the issue has something to do with the 5th gear fork. Or something related to it.





So the issue is angluar rather than smooth 5th gear engagement. When I shift from 4th to 5th , I seem to hit something hard and bounce to fifth. Can't engage with one smooth action but need to stop at neutral push the lever more to the right and then engage the fifth. This hard corner on the way is most likely the reason I snapped the 5th transfer fork.
When I simply keep banging on the obstacle it seems to move the fork in the picture, if the bolts are loosenned that is.

Any ideas? I intend to try on another fork just for the hell of it and then perhaps make an "open top" tailhousing to see what hits what. But some advice from more experienced builders would be more than welcome.

[exboyracer]

Re: Escort Sigma 1600 Race Car

Are you sure it's not just to do with the blocking bar in the tailshaft? Assuming the reverse blocking arrangement is the same as a type 9 that is.

[Roadsport]

Re: Escort Sigma 1600 Race Car

Right, this is where the lack of experience steps in. Could you explain the blocking bar? The SL is quite similar to type 9. the shifters / transfer forks are similar, only bulkier.

[exboyracer]

Re: Escort Sigma 1600 Race Car

I'm not sure I'm going to be able to explain it properly, but here goes...

On a type 9 box there is a lip in the inside of the gearstick housing which 'blocks' reverse until you push the gearstick down, when a cutout in the gearstick allows the lever to travel past the lip in the housing and engage reverse.


Thinking about it, it's not the same thing at all but I do remember that some of the cheaper 'quickshift' gearlevers are rough going into 5th gear. Might be worth trying a standard type 9 stick if it will fit?

[Roadsport]

Re: Escort Sigma 1600 Race Car

Ah, got it. Trying a STD lever is a good Idea. However I'm not too hopefull to find my problem there since this gearstick has been fine up untill we dismantelled and reassembled the box due to the circlip failure in the gearstick centering spring.
But then again trying a std stick is a good idea. Come to think of it the gearstick sometimes refuses to move to the right when on neutral. A slight tap on the stick releases it again. And even when not stuck it seems to be more willing to swing to the left. this phenomena is most likely related to the 5th gear engagement issue. I may have been abusing the stick too much during the circlip failure when I was unable to downshift. I may have been too keen to find a lower gear. All this does support your theory. Deffo worth a try !
Thanks EX, really thanks.

[RWD fords rule]

Re: Escort Sigma 1600 Race Car

It is hard to tell exactly what the issue is without checking it all myself, and not so easy to explain these things, one sentence can change the whole picture of what may be the cause and solution

What I have always done is to tune the gear lever fork position, both height vertically vs where the gear lever bolts onto the casing and also the position of the ball vs the end of the fork to get the correct feel and leverage, some of the short throw levers are dismally short with a very notchy way too short feel, I hate gear levers like that more so than too long of a throw, anyway what I have found is that the position of the reversing notch vertically vs where the lever is bolted onto the casing is very critical, I sometimes add a shim in between the casing and the gear lever mounting plate so that it is raised up a little, making it harder to get into reverse or if it is too difficult then the bottom of the fork is positioned too high, the reverse notch can be filed a little to make it easier to get reverse

What you said about not being able to move the lever from neutral to 5th is what I would focus on first, I have never heard of this happening

Does the lever spring back to neutral when you let go of it from far left and far right? it should come back and sit in neutral right in line with 3rd and 4th gear, there is a spring mechanism in the tail casing, this has to line up with a long pin iirc when assembling the gearbox, it could be possible to assemble the gearbox so that the spring mechanism will only work one way and not the other, iirc you have to assemble the gearbox in neutral, you would know if the neutral spring lets call it was not in right as the lever would spring back one way and not the other, this might not have anything to so with the problems you are having but it is best to check this is working

The more detail of what is going wrong the better, we will sort it out

[RWD fords rule]

Re: Escort Sigma 1600 Race Car

This is the pin I was talking about in the tail casing





Notice the selector shaft on the left of this pic, there is a brass plate with a small slot in the end, this locates on the pin above when bolting on the tail casing, it is possible to assemble the gearbox with this pin outside of the slot and to one side of the brass plate




Just thought this might help, if not moving onto the next thing, we will eliminate every possible cause!

[RWD fords rule]

Re: Escort Sigma 1600 Race Car

Some pics here that could be useful for describing what is wrong: http://www.scimitarweb.co.uk/sgwrs/v...p?f=20&t=11843

[Roadsport]

Re: Escort Sigma 1600 Race Car

OK heres my three notions of the issues after the rebuild: 1. the gearchange from 4th to 5th is not smooth. I seem to bang on a "corner" and bounce to 5th. This caused the 5th selector fork or finger to snap. 2. I feel like the stick is more to the right than it was prior the rebuild. 3. I tend to to jigle the stick =) from left to right to make sure it's on neutral. After the rebuild I noticed it sometimes gets stuck and does not want to swing to the right. It only wants to move between N and left. A slight bang on the stick releases it free to swing both ways.

Few backround observations: the reverse refused to engage propperly after the first year of use. If not held on it jumped off the gear. The Gearstick fork is heavily ground down from the other side by the Tran X folks for some reason. When the box was disassembled the reverse transfer fork was so loose on its pivot the stick did not have enough travel to lock the R propperly. Or so we thought anyway...We manufactured a bushing to make the fork movement precise this helped the reversing issue.

Having written all this I cant wait to get my hands on another gear stick.

[Roadsport]

Re: Escort Sigma 1600 Race Car

Oh right jason I thought the pin was not in the fork too but we checked that. And the stick does line with 3rd and 4th when released free. The very cause of the rebuild was thar centering spring device failing. The locking circlip jumped out of the groove and released the two ball bearings to jump around in the casing. Ended up scarring the 5th gears. After that very rebuild these issues started.

[Roadsport]

Re: Escort Sigma 1600 Race Car

I took a look at the gearstick today. I could not find anything wrong with it. It does not feel like it is fouling on anything. I removed the end plate at the tailhousing but The selector block at the end of the shifter rail moves freely from lock to lock and it engages the reverse well. I'm leaning towards a selector problem. I hope to get a better look this weekend.

[RWD fords rule]

Re: Escort Sigma 1600 Race Car

5th gear selector fork snapping previously tells a story, I would also be looking very closely at the selector fork since one broke before

[tom burgess]

Re: Escort Sigma 1600 Race Car

have you tried sliding the plate on the side of the gearbox forward and trying it again.then back and trying that?i know on a type 9 that makes a big difference as to how easy it is to get 5th.

[Roadsport]

Re: Escort Sigma 1600 Race Car

OK. I think I got the better of the SL72 Today ! The SL may have won a few battles but I sure hope I've won the war today. A good start for my new garage as this was the first real undertaking in the new garage.


Having no real clue whats causin the dodgy gearchange I went with the open top tailhaousing idea. It proved usefull. I found a reason for the sticking gearstick. The finger in the 5th selector block had razor sharp edges whereas the old one and the Ford original even more so had rounded edges. If the selector edges weren't perfectly aligned they would bind. And they did collide with every gear change from 4th to 5th. That had left a slight dimp on the selector block finger so I was pretty sure this was the correct diagnosis.
So I took the selector block out and rounded the edges.

This was my gearbox jig. Worked well.



very handy peek hole



There's your problem. How hard would it have been for the Tran - X folks to do this to begin with. This spare part Selector block had absolutely razor sharp edges. Its predecessor had a slight roundness to it.


The original Ford unit.


Tran - X Markus edition


Installed. Looking better


No binding what so ever. And the fifth gear now engages with one bang, without any extra movement or sounds from the transfer forks. Hope is restored.

Only one thing now troubles me a bit. I previously told you about my notion that after the rebuild the stick was further away from me. And it is tilted to the right! Further away from me as my car is LHD. Could it be bent ? The selector rail and the selector below the stick were fine so don't know. Tbh I'm not all that conserned.




I may order me a new stick or just try an OE one but thats not a big issue as the box now works. I may also order me a spare 5th selector block, if this one gives it can be changed at the paddock once the box has come out.

[Tristan]

Re: Escort Sigma 1600 Race Car

Good one on sorting the gearchange!