Transmission Woes Part Two

Postby David Robson (Admin) » 18 Aug 2003 21:16

One set of friction discs looked just a bit black to me.

Image

What I did find tonight was that the overrunning clutch was a little loose in the casing! The set screw was loose and you could wobble the ring slightly.

Image

I tightened everything up and re-staked around the ring and onto the screw.

Image

For those that don't know what this bit looks like here it is with the rollers and springs in place. It is a very important bit is this. See how the rollers prevent it turning counter-clockwise? If this bit fails...BOOM! Look Hans - no feet!

Clearance between snap ring and planetary gears is a tight 22 thou. Well within the 10-35 thou spec.

Image
David Robson (Admin)
 

Transmission Woes Part Two

Postby Dave-R (Roppa440) » 19 Aug 2003 7:34

Oh BTW John. I have a feeling that the rear planetary drum does not rest against that inner ring on the overrunning clutch. It goes through it and there is clearance each side I think. I was going to double check this point but it went out of my head when I found the overrunning clutch was loose.
Dave-R (Roppa440)
 

Transmission Woes Part Two

Postby Dave-R (Roppa440) » 19 Aug 2003 8:23

Just in case any of you out there have not see this have a look at this link.

http://www.mopartalk.co.uk/cgi-bin/discu s/show.cgi?tpc=6&post=36061#POST36061

This is what can happen if this one way clutch fails.
Dave-R (Roppa440)
 

Transmission Woes Part Two

Postby John P (Blue) » 19 Aug 2003 16:32

Hmm, Those clutch plates look pretty good to me, I was expecting them to be a lot worse than that, are there hot spots on the steels? good job you checked that the clutch was tight in the case, that was an accident waiting to happen. I'm at a bit of a loss to explain why the inner ring has worn so much against the case if the rear drum isn't resting aginst it ,I assume it wasn't like this when you last had the box apart?
John P (Blue)
 

Transmission Woes Part Two

Postby Dave-R (Roppa440) » 19 Aug 2003 16:57

Err. You expecting me to remember a detail like that with my memory?

I do remember checking the overrunning clutch for tightness. If the inner ring had been like that I might have wondered about it at least but I don't remember anything about it. I would have cleaned off any sharp edges for sure and again I have no memory of having to do that. I meant to check what the rear drum seats against but forgot (see?). I assume it is the neck of the output shaft support? It sticks through the inner race from the rear.

Yes there are hot spots on the steels but again not as bad as I would have expected.

Bear in mine Blue that these are the same friction plates that were slipping like mad that first time I built the trans and left out the outer piston seal by accident!

Give me a break. It was my first time!

They didn't look as bad as this back then and it was slipping like hell. I had to replace the steels with the old ones as several had heated so much they were warped! The friction material itself is worn almost down to the bottom of the grooves. Another thou or two and the grooves would have been rubbed out completely.

Also bear in mind that it was not slipping under normal driving conditions. It was only on the sticky track at WOT that it was slipping and I put a stop to that as soon as I realised what was happening.

The bits I need have arrived from Duncan. (Cheers Duncan!) But Diana is moaning about how much time I am spending "ignoring her" in the garage so I might have to have a night off.

But I do no how to sweet talk her so....
Dave-R (Roppa440)
 

Transmission Woes Part Two

Postby Dave-R (Roppa440) » 19 Aug 2003 22:03

Nothing goes right.

The two small hook-type seal rings (for the clutch pack input shaft) supplied with the TCI rebuild kit are too small! The shaft is 29.51mm diameter. The two seal rings supplied are only 28.93mm diameter with the two hooks linked with no compression. They are not even going to touch the sides!

I decided to re-install the two seals that I had on there to start with and I broke the hook off the end of one of them. Then it snapped in half as I took it off!

Ever have one of those days?
Dave-R (Roppa440)
 

Transmission Woes Part Two

Postby John P (Blue) » 20 Aug 2003 18:01

I have plenty of those days Dave! As mentioned elsewhere, those thin B&M clutch plates don't seem to last too well, I had to look at Pauls transmission after he lost 2nd earlier in the year, all the plates were worn smooth, this wore out in 2 years, at a guess, 3000 street miles and maybe 40 runs.
John P (Blue)
 

Transmission Woes Part Two

Postby Dave-R (Roppa440) » 21 Aug 2003 7:52

Duncan is sorting out a couple for me John thanks. Gave me some extra tips too. I must sign him up to this board.

How come you have plenty? They are not the sort of thing you you normally find boxes of in a normal garage are they?

With my luck they came free with "crunchy nut cornflakes" that week I had "fruit'n'fiber" for breakfast instead.
Dave-R (Roppa440)
 

Transmission Woes Part Two

Postby Graham Shortreed (Transma » 22 Aug 2003 3:40

Dave. If you can't locate those sealing rings, drop me a note. I've got them. I can drop them in the mail for you.
Graham Shortreed (Transma
 

Transmission Woes Part Two

Postby Dave-R (Roppa440) » 22 Aug 2003 7:21

Got that covered thanks Graham.

The trans has got to take a back seat for a few days now. I am going down South ("doon sooth") tomorrow to help Jeff Brown get his Pro Street Coronet back up and running. Hopefully for good this time? Of course it will need a good road test too...
Dave-R (Roppa440)
 

Transmission Woes Part Two

Postby Graham Shortreed (Transma » 22 Aug 2003 15:08

Here are the thickness of the clutch plates on all 727 transmissions(1962 to present date)
A: The front(also known as the direct or high reverse plates measure .095" thick.
B: The rear (also know as the forward plates)measure .062" thick.

Don't think on saving those friction plates Dave. Once plates get hot(burnt), they lose their integrity. Replace them.
Graham Shortreed (Transma
 

Transmission Woes Part Two

Postby Dave-R (Roppa440) » 27 Aug 2003 13:47

The book that Blue recommended to me came in the post yesterday.

I found something interesting in it while reading on the toilet.

In 1980 they had a problem where the snap ring groove in the output shaft bearing was not machined right and this caused the output shaft to move rearward. This causes the inner race on the overrunning clutch to press against the back of the case causing the wear and metal shavings problem we had. It also leads to failure of the overrunning clutch. Failure of that can lead to a trans explosion.

So how would this 1980 problem effect us?

Because our output shaft bearing is not in the trans. It comes already fitted into the new tailshaft/adaptor that the overdrive fits onto....

If that adaptor/tailshaft sits the bearing a fraction of an inch too far back it would cause this.
Dave-R (Roppa440)
 

Transmission Woes Part Two

Postby Dave-R (Roppa440) » 27 Aug 2003 14:08

Ah!
That would also explain why I now need a thicker 100 thou washer at the back of the pump to take up the input shaft end play!

Amazing what you can learn from a book.
Dave-R (Roppa440)
 

Transmission Woes Part Two

Postby Dave-R (Roppa440) » 27 Aug 2003 14:33

What am i talking about?

The output shaft bearing is fixed to the shaft. It is the circlip that locates it in the tailshaft. The gear vendors tailshaft must locate the clip slightly rearwards. I remember it was a pig to get on.
This must have pulled the output shaft back and squashed the inner race of the overrunning clutch against the back of the trans case - removing any end play I had set up in my first re-build. It must have got pretty hot in that clutch. Expanding it and making it loose in the casing...

But now i have the correct end play with the gear vendors tailshaft as the inner race cut its own seat into the case. The extra oilway I have provided should keep it cooler as well.

Because the output shaft is now a few thou further back I now have too much end play on the input shaft.
So all I need now is to replace my 84 thou thrust washer on the back of the pump with a 100+ thou washer and all will be right again.
Dave-R (Roppa440)
 

Transmission Woes Part Two

Postby Dave-R (Roppa440) » 27 Aug 2003 17:25

But what caused the trans to slip on the track?

My theory on that is the filter got clogged. Fine at normal rpms. But at high rpms it cannot flow enough oil for demand and as the car screams down the track the line pressure drops off and the clutches start to slip.

Does that sound likely?
Dave-R (Roppa440)
 

Transmission Woes Part Two

Postby Dave-R (Roppa440) » 31 Aug 2003 15:56

Well.

With lots of help from Duncan Watts and that very useful book on the 727 by Carl Munroe I now feel the trans is ready to go back in the car.

I just need some good weather and someone to lend a hand to mate it to the engine and I will be back in business!

Image
Dave-R (Roppa440)
 

Transmission Woes Part Two

Postby Duncan Watts (Cannonball) » 31 Aug 2003 17:39

hey dave glad you got the box back together shame i dont live close by i would give you a lift in with the tranny , would like to try out your car with the package you have hope all is well once fitted
Duncan Watts (Cannonball)
 

Transmission Woes Part Two

Postby Dave-R (Roppa440) » 01 Sep 2003 7:21

Thanks Duncan. It may not be the fastest on the strip but it sure drives well on the road.

Do you still have that RoadRunner with the Superbird wing on the back? I know you love your Challenger but I really liked that 'Runner. It was more my kind of thing.
Dave-R (Roppa440)
 

Transmission Woes Part Two

Postby Dave-R (Roppa440) » 01 Sep 2003 20:42

Well I did it. I got the damn thing fitted all by myself.

With the help of a trolley jack, a sizzors jack, several bits of wood, a sheet of cardboard to slide the trans under the car on, and lots of swearing, I managed to get the trans bolted up in about an hour and a half.

If I could have got the trans under the car while on the jack it would have taken just a half hour. An hour was spent just lifting the sucker onto the jack under the car with very little room.

It was dark for the last half hour too. Glad i did it though. It means i am well on my way to getting it going again.

I even remembered to fit the torque converter first this time! Image
Dave-R (Roppa440)
 

Transmission Woes Part Two

Postby Dave-R (Roppa440) » 09 Sep 2003 15:09

Last night was the first night since getting the trans in that I have had time to work on the car.

All did not go well. I fitted the trans crossmember bolts and all of the bellhousing bolts except for the one that the trans dipstick tube bolts to.

For some reason the dipstick tube would not go far enough in to allow the bracket on the tube to line up with the bolt hole in the bellhousing. I must have pushed and pulled on the damn thing for ages.

Now I recalled that I had been in this situation before. But my bad memory was acting up again and I could not think what the solution was.

Eventually I decided to remove the trans oil pan and have a look at the problem from below.

I saw the problem straight away. The thick pan gasket was in the way of the bottom of the dipstick tube. It was then I remembered having to cut this part out sometime before in the past.

With the pan removed the tube slipped home OK and the last bellhousing bolt went home. After trimming the inside edge of the gasket in a couple of places I re-fitted the pan and it went up no bother. I have yet to torque them up because just then I got the call to dinner and it was getting dark so....

I hope things go quicker tonight otherwise I will not be racing on Sunday!
Dave-R (Roppa440)
 

Transmission Woes Part Two

Postby Tim Ellison (Tim) » 10 Sep 2003 7:50

Everything's crossed Dave.

Good luck.
Tim Ellison (Tim)
 

Transmission Woes Part Two

Postby Tim Ellison (Tim) » 10 Sep 2003 7:50

Everything's crossed Dave.

Good luck.
Tim Ellison (Tim)
 

Transmission Woes Part Two

Postby Phil Raynor (Philth) » 10 Sep 2003 9:14

Yeah, I third that - good luck Dave, hope it's fixed for good this time!
Phil Raynor (Philth)
 

Transmission Woes Part Two

Postby Dave-R (Roppa440) » 10 Sep 2003 11:47

Luck has not changed for the better. I realised last night that I had not torqued up the two large bolts that go into the very bottom of the bellhousing. The two that go in from the engine side?

Well one of them stripped the thread didn't it and it had to be the one on the passenger side where I still have the headers in place. Image

I did manage to work a tap into the hole and used a longer bolt. That sorted it but, again, it took up a lot of time. I did however have time to replace a large section of damaged header wrap on the drivers side header (Thanks Tim).

Bad light also meant I could not see why the new mini-starter would not fit. It was a half hour before I sought out my small torch and then I could see the plastic bit on the top fouls the block. I take it you just remove this??
Dave-R (Roppa440)
 

Transmission Woes Part Two

Postby Jeff Brown (Jeff) » 10 Sep 2003 12:04

Some of those mini starters need to be "dressed" very slightly with a grinder Dave. Also the connections sometimes have to be modified... the plastic block comes off, when that is off all will be obvious.
Jeff Brown (Jeff)
 

Transmission Woes Part Two

Postby Dave-R (Roppa440) » 10 Sep 2003 12:16

I already dressed the back of it as it was touching the block too. I will try again tonight with the plastic bit removed. I will be home over an hour earlier tonight so should get a lot more done.
Dave-R (Roppa440)
 

Transmission Woes Part Two

Postby Tim Ellison (Tim) » 10 Sep 2003 12:24

Had the same problem with mine Dave. I think I ended up having to notch the headers very slightly on that side (?). Well worth the effort though, the engine fires without any hesitation since I fitted it.
Glad the header wrap helped out.Image
Tim Ellison (Tim)
 

Postby dave-r » 24 Oct 2003 8:15

Just to end this thread...

When I got the car running again it was much better. Ran the fastest it has ever ran on a strip.

The only problem I have had since was a sudden and heavy leak of fluid from the seal around the gear selector shaft on the trans. I was able to replace this seal without having to remove the trans again.

Not a drop has leaked since.
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Postby 72 Challenger (Hans) » 24 Oct 2003 8:26

And you did this run Dave? Watch it when Linda drives it :lol:
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