727 rattle/vibration

Arran · Post by **Arran** » Sun Jun 14, 09 11:55 am

I,ve just hooked up coolant temp and oil pressure guages to the Dart so I can run the engine for a bit longer than previously now I know what temp she's at, and I've got some serious vibration at about 2000rpm and some horrible rattling noises at idle from around the bellhousing/front of trans at idle. I,ve checked flex plate and bolts and they seem fine. She moves forward and back although first is a little slow to select when slightly warm. Fluid level is fine.I cant drive her on the road yet (although I may put the trade plates on her next week and go round the block

) so can anyone tell me if this is a torque converter problem or an internal trans issue? Is the trans overhaulable by a relatively competent mechanic? what overhaul kit would you suggest and if I'm in there, what shift kit would be best for occasional strip use?
Sorry for all the questions but I thought I'd ask them all in one hit

MilesnMiles · Post by **MilesnMiles** » Sun Jun 14, 09 3:06 pm

That sort of noise around rge convertor is often the bolts. have you chaecked them thoroughly .ie.taken them out, loctited and re fixed? The bolts do not have to be visibly loose to hit the bellhousing. Mine were just a half turn loose and clouted it.
For street/occasional strip use Trans Go shift kit. Mine gives firm, as in banging them in under firm throttle shifts without overlap. about £75, I think alders got mine off the shelf.

TrevD · Post by **TrevD** » Sun Jun 14, 09 6:59 pm

is it the original trans, convertor and flex plate, if not it might be wrong for your aplication, some are ballanced differently to others (internal or external ballance).

Arran · Post by **Arran** » Sun Jun 14, 09 10:42 pm

I,ve been underneath with it running at idle and the noise is slightly further back than a noise from Bananarama! the block and I am totaly sure they are tight

I am sort of hoping that it is the torque converter so that I can strip the trans at my leasure rather than having to so that I can use the car, but I have no idea what a knackered one would sound like. Can they break up inside and have bits of impeller or something rattling around?
I,ve read a little about the transgo kit on the Allpar site and it sounded good so I may try that one, thanks.
Trev, are they just balanced to each other or to the motor as well?
What happens when you stick in another converter? does the whole lot have to be rebalanced?

As for originality, is the converter stamped with anything to identify it to the trans or the flex plate?
This is all a bit of a pain cause I thought my next outlay was to be nice new wheels or exhaust

MilesnMiles · Post by **MilesnMiles** » Sun Jun 14, 09 10:46 pm

convertor depends on engine balance.What motor do ou have?
Either way, it wont suddenly go out of balance if it is a matched trans/convertor/flex/motor combo.

Anonymous · Post by **Anonymous** » Sun Jun 14, 09 10:55 pm

Maybe the trans mount?

Arran · Post by **Arran** » Sun Jun 14, 09 11:02 pm

All motor and trans mounts are good

The motor is a 340 but I dont know if its numbers matching to the trans. I,ll check tomorrow. What happens when you change any one of the four items? Surely it can't all need rebalancing and if it does, how?

MilesnMiles · Post by **MilesnMiles** » Mon Jun 15, 09 10:46 am

Check my info, but I believe that 340s came with internal balance, 360s are definately external balance.
you need to know if either trans/engine/convertor had changed.

Is the vibration when running the car, or static? If running, UJs, pinion bearing in rear diff, propshaft out of balance. As brutus sez, trans mount. Check to see if it really is good. Mine vibrated horribly until I changed it.
More surreally, I rotated the propshaft round and re attached; end of vibration.
All of the above aside, the only knocking rattling sound I ever had came from the convetor bolts being loose.

Anonymous · Post by **Anonymous** » Mon Jun 15, 09 4:31 pm

I have a vibe too, but only at 110+mph

I think that the rear Tyre's are the fault BIG YANK Goodyears

mopar_mark · Post by **mopar_mark** » Mon Jun 15, 09 9:47 pm

PaulW wrote: I have a vibe too, but only at 110+mph

That's annoying, just before the 3rd shift. One it's changed gear does the vibration disappear ?

Arran · Post by **Arran** » Mon Jun 15, 09 10:40 pm

Checked numbers on trans and motor today. Nothing matched

The vibration and noise is all while stationary (not moved more than a few metres under its own steam yet

). I will recheck the mount tomorrow.
there is a posibility the vibe could be motor related i spose as from what I've read, the 340 crank and damper are balanced together but I have had the damper off and couldn't find a casting number on it anywhere so I have no idea whether its the right one or not.Can I run the motor with the trans out if I drain and refit the torque converter?. Does anyone know how this lot can be rebalanced together?

MilesnMiles · Post by **MilesnMiles** » Mon Jun 15, 09 10:52 pm

i'm no expert, but you mention 'horrific' noises. You could try ad upload some phone images/noises. Only such noises i've had come from engine breaking up, can pick it up from the exhausts.
Does it make the noise whilst in gear? could try using a length of hose against where you think the noise is coming from to eliminate certain parts.

Arran · Post by **Arran** » Mon Jun 15, 09 11:01 pm

'Horrific' was maybe a little strong for the noise but the vibration is pretty bad. Tomorrow lunchtime I'll stick it on the four poster and get the stethoscope out to pinpoint the noise.
I was thinking of doing a little video and putting it on utube but I need to work out how to do that first.

Anonymous · Post by **Anonymous** » Mon Jun 15, 09 11:21 pm

mopar_mark wrote:
PaulW wrote: I have a vibe too, but only at 110+mph
That's annoying, just before the 3rd shift. One it's changed gear does the vibration disappear ?

Arran · Post by **Arran** » Tue Jun 16, 09 9:16 pm

Just read another thread relating to trans noise in muslecar lounge and PhilB described my exact symptoms! His problem was the converter so I think I'm going to have to pull the trans, take off the converter and give it a shake (is this the prefered method of testing

)If it is the converter, any recomendations of what to go for and roughly how much or are they repairable?