Got a couple of questions regarding the "modification" of 5th gear.
Here is a shot of my 5th gear.
Right now, there is no issue. I have all gears, no noises and shifts fine. I would like to "fix" 5th gear before it becomes an issue. I know it's recommended to weld it up to prevent it from freewheeling. Where exactly should this be done? I was also thinking of the possibility of torquing the nuts to spec and drilling and pinning the nuts with a hardened roll pin and spot welding the pins in place. This would make removal much easier should repairs be required in the future. Will this work? Anything else I should be looking for?
I'm also a little concerned about the condition of the (I think) reverse idler gear. Seems a little chewed up. Take a look (above pic is a little better)
Finally, I believe this is a brass syncro trans. (Came out of a 70') Can someone confirm by the blurry pic? (I really need a new camera!)
Its hard to tell from your pictures, but it kinda looks like a syncro box. As for 5th gear, it will depend on if its a pressed 5th or a splined 5th. The only way to tell is to pull it apart and look. Some place I have a picture of my last dead 5th showing the sheared welds. I'll dig around and see if I can find it.
Will
Sorry, I find modern engine swaps revolting. Keep your G, R, or U series in your Roadster!
Look at the steel syncro the 5th gear has. All 5 speeds I have seen have this type. If 1st through 4th's syncros look like 5th you have a steel trans. It appears from the fuzzy pix yours is a brass box. The last time I rebuilt a brass box (2002) the syncros and bearings were around $125. CDM was the source. I have changed over to the steel type because it stands up better to my thrashing. I would wear out the brass syncros and the transmission would allow one of the the 3 dogs? under the gear sliders to pop up and lock in that gear. Once it happened in 4th. Was able to make it home and sacrificed the clutch. The other time in 2nd. Tow time. My suggestion, do the "as long as" dance. As long as you have it open ...... Pay attention to the shim specs on a brass box. Too much play will allow the "locked in gear" effect to happen sooner.
the reason I was thinking it might be a servo box is that the brass syncros usually look much brighter. The one I have if you look through the fill hole, the syncros are bright and obviously brass.
Will
Sorry, I find modern engine swaps revolting. Keep your G, R, or U series in your Roadster!
It's a borg warner (brass) box.
As Will said, you've got to take 5th off the shaft to see if it's splined.
In my opinion don't waste your time with trying to weld the gear - buy a splined one.
No need to weld the main shaft nuts. The double nutted main shaft fixes the issue with the nuts backing off the shaft so long as they're assembled correctly. I don't remember the torque spec for tightening the front most nut against the gear cluster but I think it's 25ft-lbs. After which the jam nut is snugged up behind the main nut and then the important part is that the main nut is backed off against the jam nut at 225ft-lbs.
It won't budge after that.
The comments about the warner box sticking in gear are the main concern with the brass ring boxes. I've never had it happen but I'd been told years ago that that specific issue is why racers prefer the servo box.
As far as durability goes - there's been a lot of talk lately about the warner box not being very stout which seems to give the impression that it won't take abuse. Not so. I've thrashed the crap out of mine for years now including autocrossing it regularly and other than begining to wear out the second gear synchro (which you'd expect) it holds up fine. That said, the servo box is stronger but the warner box is not weak.
All of them have potential issues with the roll pins on the shift forks shearing so it's a good idea to replace the standard roll pins with double rolled pins.
That's "torque spec" not "torque sped"-fixed by SA
Time for another cup of coffee.
By the way, the reverse idler seems quite serviceable - mine looked like that too. If it really bothers you though, it's easy to replace. Otherwise, just try to control shifting into reverse with the car moving.
Perhaps you shift differently than me. My brass ones would last about a year than POP, stuck again.
I always hit 5th gear just before reverse. Stops any grinding issues. The people who do the yearly state inspection don't do this and usually grind reverse!!!
You can take the idler off, put it back on the shaft backwards than install the two washers and the clip. A little harder to put into reverse but you get a larger contact of the gears.
The reverse Idler gears always get hammered. You can have someone face the front of the gear if you want, but it will just happen again, and eventually get worse...New idler gears are about $85.00 your new one will look like you old one in a couple of weeks of use. The problem is from shifting down from 5th to 4th, if you dont shift carefully you will clip the reverse idler and chew it up a little everytime you downshift.
The torque specs do work for most street applications we modify our race boxes because they take a lot more abuse. We do weld 5th gear....and we modify the jam nuts and use a later model jam nut to make sure that they will not loosen up while racing.
67.5 2000, SRL 311 000305 Solex
A race car since new!
Instagram #RC240Z #geoskyalert
The problem is from shifting down from 5th to 4th, if you dont shift carefully you will clip the reverse idler and chew it up a little everytime you downshift.
Yup, you gotta be more careful with that particular shift.
Last edited by 23yrRebuild on Sun Apr 05, 2009 11:45 am, edited 1 time in total.
Is there any practical way to make a reverse lockout? I'm not racing, but have buzzed reverse on a sloppy 5-4 shift.
Also, if you can see the syncro, can you reach it with a little telescoping magnet through the oil hole? That will verify steel or brass.
Dave Brisco
Take my advice, I'm not using it"
66 2000 The Bobster
64 1500 in pieces for sale
1980 Fiat X1/9
2009 Volvo C-70
08 Expedition EL, STUPID huge but comfy
1962 Thompson Sea Lancer, possible money pit
I fail to understand why people want to go overkill on the tranny's big nuts. Every time I go to remove them they are just as hard to get off as I put them on. Very fine threads seem to stay torqued down just fine.
Dbrick some guys that race remove reverse all together, although it is not recomended. The other solution is to cut back the reverse idler gear so that it is harded to graze while shifting from 5th to 4th. But this weakens that gear and again is not suggested.
I have not looked into a lockout for my transmissions...but it is not a bad idea.
Ron
67.5 2000, SRL 311 000305 Solex
A race car since new!
Instagram #RC240Z #geoskyalert
OK, finally got the right tools (1 1/2" end wrench and 1 1/2" crowsfoot) to loosen the double nut. That sucker was tight! Anyways, not quite sure where the problematic 5th gear is. Here are a couple of pics I just took. I need to remove the roller bearing to fully disassemble the gear assembly but my press is outside and it's dark (and I'm too lazy to drag a light out). I hope someone can answer if I have the splined 5th or not without further disassembly.
I am not sure if I'm looking in the right area.
Here is an "exploded" view. The only thing I can see that has splines on it is the 3 legged gear thing the slider goes over selecting either 5th or reverse. Is this what I'm looking for? (I hope)
Heres another closer (and fuzzy) shot of the 3 legged gear.
Or are we talking the actual 5th gear/syncro assembly that I'd have to pull off and remove the snap ring that holds it together?
