Front Shifter rod replacement questions
04-05-2008, 01:13 AM
#31
Rennlist Member
Thread Starter
Thanks stan.
I think i might take Carl up on his design. as long as it has the right amount of rotating movement, it could work.
the clutch pushrod is hardly like this joint. the ball cup has the cup rotate left and right depending on the shift, but you also dont want fore and aft movement due to the force from shifting gears. you are proably right that the Carl part probably wont wear, but you never know. by the way, the heat is no where near liquification of the plastic insert. However, it does wear, and even when cold, even my 2 year old part has some play in it.
I just noticed that the part that 928intl sent me has a curved area before the linkage shaft. mine is straight. did they change this for different years?
anyway, dont think it will work because of this.
anyway, my quick fix will work for the weekend. the Holbert car will be on display at the "Festival of Speed" in downtown San Jose this weekend.
mk
I think i might take Carl up on his design. as long as it has the right amount of rotating movement, it could work.
the clutch pushrod is hardly like this joint. the ball cup has the cup rotate left and right depending on the shift, but you also dont want fore and aft movement due to the force from shifting gears. you are proably right that the Carl part probably wont wear, but you never know. by the way, the heat is no where near liquification of the plastic insert. However, it does wear, and even when cold, even my 2 year old part has some play in it.
I just noticed that the part that 928intl sent me has a curved area before the linkage shaft. mine is straight. did they change this for different years?
anyway, dont think it will work because of this.
anyway, my quick fix will work for the weekend. the Holbert car will be on display at the "Festival of Speed" in downtown San Jose this weekend.
mk
04-05-2008, 01:57 AM
#32
Rennlist Member
Thread Starter
Im wondering if the bent tubing is for the earlier model years, due to the fact that the spacing on the shift lever is wider. This is interesting, as when i used the 1984 shifter mechanism with the 1985 transmission, i suddenly had a short shifting set up! im thinking that the conversion might be as simple as using the early front tube set up, with the early shift lever.
mk
mk
05-05-2008, 12:00 PM
#33
Rennlist Member
Thread Starter
SORRY, you are wrong, it lasted the entire race and then broke on the way home. 
Well, now i got to figure out how to get those two 10mm nuts off to replace the thing the right way now!
Thanks, It almost cost me the race as you said. actually, the part welded was fine, it was how it fit together that started to move up and down, shearing the bolt.
MK
Well, now i got to figure out how to get those two 10mm nuts off to replace the thing the right way now!
Thanks, It almost cost me the race as you said. actually, the part welded was fine, it was how it fit together that started to move up and down, shearing the bolt.
MK
Hey Mark now that your done experimenting, I would suggest that you call Carl and get one of his front shift rod couplers and get yourself a new front shft rod, have some extra metal welded on around the shifter bracket , and the shifter pins also touched up with the welder. Since you have a hole in the floor installing these parts should take not more than an hour.Then you can forget agout it!
Your repair though holding will soon fail and the front shift cup is not far behind. Some of this is proofed by you already drilling a hole for a roll pin, that out to work for for about 2 spirited laps
Your repair though holding will soon fail and the front shift cup is not far behind. Some of this is proofed by you already drilling a hole for a roll pin, that out to work for for about 2 spirited laps
05-05-2008, 02:03 PM
#34
Team Owner
Mark see post 25 good luck
05-05-2008, 03:15 PM
#35
Rennlist Member
Thread Starter
Hey, when you are right you are right. I cant tell you how many times this weekend i was praying for it to hold. the prayers paid off right until the last lap where it started bending up and down, the joint. by the time i got 5 miles from home, it snapped. vise grips for the way home in 2nd and 3rd gear! 
the last lap, your words of wisdom was HAUNTING me! I was noticing how much force you do use on the gear shift during racing, even with smooth shifts. If they are fast, its all about F=ma. who knew
So, thanks. Its coming apart. Hope i can get to those 10mm nuts to remove that bearing holder.
Mk
the last lap, your words of wisdom was HAUNTING me! I was noticing how much force you do use on the gear shift during racing, even with smooth shifts. If they are fast, its all about F=ma. who knew
So, thanks. Its coming apart. Hope i can get to those 10mm nuts to remove that bearing holder.
Mk
Mark.
Do this remove the exhaust, remove the heatshields , pop off the ball cup with a small 10mm wrench undo the securing nuts for the forward shaft holder above the TTube. You should be able to slide the piece forward and out. With your new parts(used) I would weld an additional piece of metal to the junction of the shifter connection and also weld some extra to the shifter pin. Refit the new rod with the support on it then screw in you new shift rod coupler and use loctite on the securing nuttest all of the connections then go racing.
From looking at the failures you have had i would say you have been overstressing the parts in the heat of racing, thus your failures, it would suck to lose a race because the fatiged shaft/ball coupler failed
Do this remove the exhaust, remove the heatshields , pop off the ball cup with a small 10mm wrench undo the securing nuts for the forward shaft holder above the TTube. You should be able to slide the piece forward and out. With your new parts(used) I would weld an additional piece of metal to the junction of the shifter connection and also weld some extra to the shifter pin. Refit the new rod with the support on it then screw in you new shift rod coupler and use loctite on the securing nuttest all of the connections then go racing.
From looking at the failures you have had i would say you have been overstressing the parts in the heat of racing, thus your failures, it would suck to lose a race because the fatiged shaft/ball coupler failed
05-06-2008, 02:03 AM
#36
Rennlist Member
Thread Starter
Forget all that, "drop exhaust, heat shield" etc stuff.
Its a race car. I just cut a hole just behind the shifter area and used a 10mm socket!!
pulled out some foam and pushed it through. I might be able to change this thing out without spending too much time under the car.
Mk
Its a race car. I just cut a hole just behind the shifter area and used a 10mm socket!!
pulled out some foam and pushed it through. I might be able to change this thing out without spending too much time under the car.
Mk
05-06-2008, 03:38 AM
#37
Team Owner
well if yer gonna hack things up I guess its easier for you to do it this way
05-07-2008, 01:47 AM
#38
Rennlist Member
Thread Starter
i would hardly call a small 1"x 3"hole, in an area never seen , "Hacking things up"! But, i just spent 30min fighting to get the shifter shaft out with the bearing attached. there is not much room with the headers and the torque tube so close together. even tougher putting the new one back in.
anyway, its done. should have done this a month ago!
Thanks for the comments. You were right! What the heck was i thinking!
mk
anyway, its done. should have done this a month ago!
Thanks for the comments. You were right! What the heck was i thinking!
mk
05-07-2008, 03:31 AM
#39
Team Owner
I guess i could have used the word cut instead of hack, glad she finished i hope that you had some additional welds placed on the pins that go into the shifter, they seem to snap with spirited driving. Keep em flying.
So Mark, you never said if you are using Carls front shifter ball replacment part???
So Mark, you never said if you are using Carls front shifter ball replacment part???
