Part identification quiz

[nick]

This part is next to a US 5 cent coin. The coin is 7/8" diameter. The part is about the same thickness as the coin. I found it stuck to the mag pickup on the gearbox drain. The ID of the part is very close to the OD of the coin.

The gearbox has a known problem. It jumps out of 3rd gear when the throttle is modulated at a normal rate.

It looks like it could be part of a clip or ring. Any guesses[8D]


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nick
'79 TR7 DHC
'76 TR7 FHC

[Beans]

4 or 5 speed 'box?

I can't remember seeing something slightly similar in a 5-speed 'box
As it was stuck to the plug I presume it is steel?

The only bit I think of that comes close is the O-ring from the selector shaft ...

http://tr7beans.blogspot.nl/2011/09/preparations-for-return-of-dhc.html

<center>
<font color="blue"><i>1980 TR7 DHC (my first car, now restored and back on the road)
1981 TR7 FHC Sprint (better known as 't Kreng)</font id="blue">
<b>[url="http://www.tr7beans.blogspot.com/"]<u><b><font size="3"><font color="red">My full Weblog</font id="red"></font id="size3"></b></u>[/url]</b></i></center>

[claypole1360]

Been firtling through a bag of stuff in the garage, the stuff was cogs from a spitfire overdrive gearbox rebuild. It looks a bit like a shim.
Clayps.

What's that coming over the hill? Is it a monster?

1978 TR7V8 FHC
1968 Bond Equipe Sprint Car
1962 Herald Coupe 1200
2003 Peugeot 206 GTI
2009 VW Passat

[nick]

It's metal from the 4 speed I just removed. Looks like it could be circlip. I plan to open the box but I don't if I will recognize something that small missing.



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nick
'79 TR7 DHC
'76 TR7 FHC

[Beans]

<blockquote id="quote"><font size="1" face="Century Gothic, Verdana, Arial, Helvetica" id="quote">quote:<hr height="1" noshade id="quote"><i>Originally posted by nick</i>

It's metal from the 4 speed ...<hr height="1" noshade id="quote"></font id="quote"></blockquote id="quote">
You had me worried there thought I missed something, but no wonder as I never owned or opened a 4-speed 'box [:p]

<center>
<font color="blue"><i>1980 TR7 DHC (my first car, now restored and back on the road)
1981 TR7 FHC Sprint (better known as 't Kreng)</font id="blue">
<b>[url="http://www.tr7beans.blogspot.com/"]<u><b><font size="3"><font color="red">My full Weblog</font id="red"></font id="size3"></b></u>[/url]</b></i></center>

[john 215]

Hi Nick

I thought it was out of a 5 speed box and just could figure what it was [?]

Now I know its out of a 4 speeder, there is a clip like that that holds the 3rd gear to the mainshaft, it sits in front of the gear and behind syncro hub, this would also account for your 3rd gear issue.

Can be seen in this picture of the last 4 speed I rebuilt, a overdrive box box destined for my FHC -







Cheers John


LIVE LIFE A QUARTER OF A MILE AT A TIME!

1976 Speke FHC Beauty

1979 3.5 FHC(STATUS PENDING!!)

1982 2.0 DHC NOW A 4.6,ON THE ROAD NOW KICKING AR5E !!!!

[nick]

John, that's brilliant. That is the part. I expect I will find the rest of it when I open the box. Could you confirm that it is part number TKC6444 on this diagram?
http://www.rimmerbros.co.uk/Item--i-GRID006096

Any special tool required to replace it?

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nick
'79 TR7 DHC
'76 TR7 FHC

[john 215]

Hi Nick,

That the one,

No special tools required and if you have stripped other gearbox's then these are simple to do. In my dealership days we had special tools to pull out first motion shaft out of the casing ( 18G 284 ) and another one that is used to hold the mainshaft in the correct position when refitting the shaft and bearing ( 18G 47 ), if you have the layshaft out you will need a dummy shaft to hold the needle bearings in place, for all of these I made my own. If you follow the manual then you cant really go wrong. I got a rebuild kit for mine with new bearings, baulk rings,clips, gaskets ect

Cheers John


LIVE LIFE A QUARTER OF A MILE AT A TIME!

1976 Speke FHC Beauty

1979 3.5 FHC(STATUS PENDING!!)

1982 2.0 DHC NOW A 4.6,ON THE ROAD NOW KICKING AR5E !!!!

[nick]

Thanks John. Very helpful.
I have a bit of a delema. I have acquired a 5 speed gearbox, propshaft and diffential. I originally wanted to just put in the 5 speed and retain the original differential. But I could not pass up the other parts from the donor car so I grab the entire drive train.

Which way would you go. All 5 speed parts or just the 5 speed with custom propshaft and original differential?

I plan to fix the 4 speed and keep it in case I want to convert back or perhaps sell it. By the way, taking that lump out without removing the engine was no fun. I have taken the 5 speed gearbox out a couple of times but always with the engine. I thought I'd try gearbox removal only. Never again.

[img][IMG]http://i615.photobucket.com/albums/tt234/nickmi/TR7%201975/Yellow.jpg[/img]
nick
'79 TR7 DHC
'76 TR7 FHC

[john 215]

Hi Nick,

I have a 5 speed in my Speke FHC and plan to retro fit the 4 speed back in, although with a twist as will be an overdrive box as offered by Coombes ' back in the day '






A lot of people swear by the 4 speed box but also a lot of people fit 5 speed boxes, dont forget the bottom arms are different on a five speed axle, they have extention parts to control axle movement, but dare say it is possible to run 4 speed arms though as long as not to many racing starts are carried out !!

Cheers John


LIVE LIFE A QUARTER OF A MILE AT A TIME!

1976 Speke FHC Beauty

1979 3.5 FHC(STATUS PENDING!!)

1982 2.0 DHC NOW A 4.6,ON THE ROAD NOW KICKING AR5E !!!!

[catmanboo]

my understanding is that the 4-speed cars had higher gearing in rear ends.that is, higher rate of wheel rotation per a given driveshaft speed. with a 5-speed trans, you get higher top speed[:p], better fuel economy, & it stretches out your shift points. driveshaft mod needed, though, if keeping original rear end. the bit you found on the plug has another one just like it, from the same place on mainshaft floating around in there.[:0] gotta wonder how that got loose in the first place- unless excessive end-play & wear in the box. it likely has other issues, & some bits are difficult-to-impossible to find here in the states. now, that 5-speed's looking kinda good,eh?[:D]

[nick]

I've got the 4 speed and have the old 3.63:1 rear end out. I have a 5 speed waiting to go in along with a 3.90:1 differential. It was easier to change the differential then fuss with a custom drive line.

Here are the final drive ratios for the two differentials using the 5 speed gearbox:
3.90:1 diff: 1st 12.95, 2nd 8.15, 3rd 5.46, 4th 3.90, 5th 3.24
3.63:1 diff: 1st 12.05, 2nd 7.59, 3rd 5.08, 4th 3.63, 5th 3.01

Speeds in MPH at 4000 RPM with 195/60-14 tires:
3.90:1 diff: 1st 21.3, 2nd 33.9, 3rd 50.6, 4th 70.8, 5th 85.3
3.63:1 diff: 1st 22.0, 2nd 36.3, 3rd 54.3, 4th 76.1, 5th 91.6

The only big advantage I see to the 3.63:1 is 5th gear where at 60 MPH the RPM is 2620 vs 2810 on the 3.91:1 rear end.


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nick
'79 TR7 DHC
'76 TR7 FHC

[Terry B]

I don't mean to hijack the tread, but I was a little concerned by John's comment about the using 4 speed trailing arms with a five speed axle. My current project may have 4 speed arms with a 5 speed axle. Would this be an issue for normal road use.

Thanks


Terry B

[FI Spyder]

<blockquote id="quote"><font size="1" face="Century Gothic, Verdana, Arial, Helvetica" id="quote">quote:<hr height="1" noshade id="quote">
The only big advantage I see to the 3.63:1 is 5th gear where at 60 MPH the RPM is 2620 vs 2810 on the 3.91:1 rear end.
<hr height="1" noshade id="quote"></font id="quote"></blockquote id="quote">

That big advantage will be felt up and down the shift range not to mention at the gas pumps.

Disadvantage with the 4 speed diff:

No more pulling out tree stumps in first gear.

Not being able to idle along in parades without using clutch.



- - -TR7 Spider - - - 1978 Spitfire- - - - 1976 Spitfire - - 1988 Tercel 4X4 - Kali on Integra - 1991 Integra - Yellow TCT

[nick]

You can use the 3.63:1 diff trailing arms with the the 5 speed gearbox for normal driving.
Another disadvantage to the 4 speed differentials is that they can be whinny.

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nick
'79 TR7 DHC
'76 TR7 FHC