pettybludart
Well-Known Member
I don,t trust that maual,as they,ve added wrong info before.I,d rather take advise from racers that have been there,done that.Thanks for the info anyways.:cheers:
Off to the tranny shop!
- Thread starter pettybludart
- Start date
-
Larry Shepard is a racer who's been there and done it all his life including performance R&D for Chrysler. He helped pen the MP manuals, btw. IMO, I think you should be running the SS springs like the manual says too. But that's just my opinion. What the hell do I know?
fishy68
Tyr Fryr's Inc.
How does the converter snout look? If the crank to input shaft centerline is off that would wear the bushing. In that case you'll need offset dowel pins to correct it.
fishy68
Tyr Fryr's Inc.
It's been a long time since I read through the chassis manual but isn't that figure more so for the SS springs? I don't remember a specification for the XHD springs but I have them on my car and found at 6 degrees it vibrated. I have it at 4 degrees now and it seems to work real good. Hooks real good and no vibration. Then again my car is no race car. Just a 13.40 street car.
Not to shoot Larry in the head here, but, it also says you can't or it's not recommended to use a production SB block and make more than 450 or 500 hp in his book IIRC. I also think he's the one with the bullshit rear end measurement chart.
Don't know which mounts you have in the car. If solid up front, make sure you run a rubber or poly on the trans. Solid all around usually ends with a broken trans case in unibody cars.
Yup. but I also said that I thought it would be a good idea for Scott to be using the SS springs. They are race springs, after all. And it is a race car. I'll just leave it alone. It's obvious we do things differently. Sorry. I was just trying to throw some helpful suggestions out there.
Sorry to read of more tranny issues petty. Thinking along the same lines as crackedback, a motor plate made a world of difference when we were racing. Really kept the body from twisting.........And yes, we rubber mounted the trans.
moper
Well-Known Member
The pinion angle should be measured and set for YOUR car. Usually I end up around 3-4 down. but you should be looking to make the pinion angle the same as the transmission output shaft angle. If the engine sits tall on different mounts, or the SS spings are used, you may need to go much further to get the driveshaft in phase under power.
Sounds like it's definately off on the input shaft centerline.. There' a guy called Rob that has a great set of pins that work very well.
Look up http://www.robbmcperformance.com/products/dowels.html
Sounds like it's definately off on the input shaft centerline.. There' a guy called Rob that has a great set of pins that work very well.
Look up http://www.robbmcperformance.com/products/dowels.html
fishy68
Tyr Fryr's Inc.
Those are nicely designed pins.
pettybludart
Well-Known Member
Thanks for the link Moper,the pins look nice and look like they would be the ticket.I,m running the stock single pin tranny mount(rubber)with solid motor mounts(also shimmed for tranny angle)I have a feeling that when I snapped the perches,I damaged/bent my driveshaft causing vibration.Also the angle the tranny is sitting at the back of the engine(hopeing it will be fixed with the dial inicator)Harry Manovich knows his stuff and also has some good connections in the racing circle,so I have faith in him helping me get this sorted out(obviously this is my problem after building the car quickly in 6 months)I just didn,t think I would have these tranny issues.I believe this is all trial and error on my part and is part of racing $$$.Lesson learned.I appreaciate everyones help/input/suggestions.This little 408 is a torque monster and I expect to be having more breakage as I go.Oh,my XHD springs,they,re working great for my 2800 car.If the car was as heavy as my 73 Dart Sport,I would be using the SS springs.Will keep y,all informed on the outcome.:toothy10:
PS Will be looking into engine/tranny plates over the wintertime.
PS Will be looking into engine/tranny plates over the wintertime.
pettybludart
Well-Known Member
Well I picked up my driveshaft today,it was bent and out of balance.So the straightened it and rebalanced it.I guess they retubed it,cause it looks brand new.Hope this was my problem?:clock:
moper
Well-Known Member
Prob was a good part of it, yes. But the input bushing/convertor wear point to other problems too. Sometimes it's just like that. SOme thigns fall together and are perfect for years. Some wrestle you every friggin' inch. What you are now doing should be done on any build up but almost never is unless it's for a competition vehicle. Hell, I dont even do it unless a problem comes up or it's a race car...lol.
ham_r_down01
Is Freak Nasty
It only took 3 trips to the driveshaft shop to get my vibration to go away. New bushing in the back of the trans and I shimmed the axle. The last time I went there I had to explain that this is going in a race car that spins the driveshaft faster than 3000 rpm... The shaft had to be straightened and rebalanced... This shaft was brand new?? WTF So when I got it back I could see where the weight was, 180 degrees off. Not my fault and no bad vibes now, just had to dot my t's and cross my i's be persistent everything is new. The bad shaft will crack a tailshaft too, be sure to check the bushing and the fit of it on the slip yoke.
pettybludart
Well-Known Member
Yes I hope the driveshaft was part of my problem,waiting to hear if it,s done today?
dodge freak
Well-Known Member
I heard that ploy motor mounts are for street strip cars and solid mounts for the engine are race only. That solid mounts are more likely to cause crack drivetrain parts. The ploy alllows some flexing.
Yeah real race cars use motor plates also.
Yeah real race cars use motor plates also.
cjh
Well-Known Member
Put up a picture of underneath where the engine meets the tranny......shot from engine side towards the tranny.
pettybludart
Well-Known Member
Well I got my car back today,my t.converter showed up this morning and I,ll be taking it out to the track today(Sat.)for a Nostalgia event and tomorrow is Mopar Day at my local track also.:cheers:Hope everything holds together and will keep youz posted with results.:-D
Sounds like a good day....Nostalgia and Mopars. Have a great time!!
fishy68
Tyr Fryr's Inc.
Good luck with it Scott.
pettybludart
Well-Known Member
Well I,m back from a weekend of racing!The car ran great,tranny is working great.My vibration is gone(fresh driveshaft)I had a best of 11.15@120mph 60fts 1.56.Now when I get my new Hoosier 29-12-15,s on,I hope to get my 10.99 before the season is up!Alls good!
Snake
Mopar Nut
All right Scott good news,you will sleep like a baby tonight.
pettybludart
Well-Known Member
I don,t know Don about sleep after reading you can get $23K for your car.LOL.Maybe I should put the 73 D.Sport 340 up to see what it would fetch?Then search for the 68 or 69 Cuda fastback I so dearly want now!Hmmmm???
11 teens!!!! You're getting close!!! Keep up the good work. You'll get there Scott. I wish I could be there for your first 10.90's pass. Have someone take video if you can. I want to see the big smile when you do. Mike
74scamp360
Junior Member
you're getting close man, good to hear its on the track again. good luck on hitting the 10's!!
pettybludart
Well-Known Member
Yep I,m borderline on a 10 sec. pass.The car ran 11.17@118 this weekend and it was 100% humidity.The car should,ve ran slower?[ame="http://www.youtube.com/watch?v=bmKML5BWhkY"]YouTube - Racing the 66 Dart 063[/ame]
-
