LT77 speedo sensor

LT77 speedo sensor

Author
Discussion

bubblehead

Original Poster:

264 posts

131 months

Saturday 3rd September 2011
quotequote all
Hi all, does anyone know the part number for the above or have an old/new one they want to sell or any leads on stockists etc.
Cheers.

5.0ltr

2,478 posts

137 months

Ant.

5,250 posts

219 months

Saturday 3rd September 2011
quotequote all
What is the problem with yours?

Be aware( you may already know, there are two different pulse values), you need to know before buying one.

Have you got yours out?

I am no longer using the one in my box, but need something to blank the hole off......

bubblehead

Original Poster:

264 posts

131 months

Saturday 3rd September 2011
quotequote all
Ant. said:
What is the problem with yours?

Be aware( you may already know, there are two different pulse values), you need to know before buying one.

Have you got yours out?

I am no longer using the one in my box, but need something to blank the hole off......
Hi Ant, not got it out yet as i'm away from home, it's Lordgrover's old car that i've bought so it's been dodgy for a while. The speedo works fine when cold but gives up once warm and searching previous posts suggests the sender/sensor is the problem.

bubblehead

Original Poster:

264 posts

131 months

Saturday 3rd September 2011
quotequote all
5.0ltr said:
I think they are for the later cars, the precat uses a drive off the gearbox, need to update my profile......
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Barreti

6,535 posts

175 months

Monday 28th May 2012
quotequote all
I'm reviving this old thread to keep all LT77 speedo sensor information in the same thread.
I hope the OP is OK with this.

I'm hoping someone knows where I can get a speedo sensor for a pre-cat with the LT77 box and the sensor in the side of the box.

Both the links above refer to sensors on the diff not the gearbox.

I think mine is on the way out because the speedo has become really intermittent.
It will do nothing for 20 miles, then suddenly spring to life for 10 miles or so before going back to sleep.
I'll test the sender before buying a new one obviously but at this investigation stage I don't even know where to go should I need one.

Ta.
IanB

JamesK

2,122 posts

217 months

Tuesday 29th May 2012
quotequote all
Strangely I now have exactly the same problem. Coincidentally (or not), since I recently had the box dropped to change some plastic bushes/linkages my speedo has developed what seems to be a loose connection in that if I go over a bump it sometimes dies and comes back again after the next bump.

This is coupled with the occasional brain fart about moving engine idle - sometimes wants to cut out whan approaching a junction etc. I've read conflicting stories about location and number of feeds from a pre-cat sensor but looking at my circumstances mine seems to be from the gearbox and feeding both speedo and ECU?

NO help at all but I'm watching what Ian does with interest smile

bubblehead

Original Poster:

264 posts

131 months

Tuesday 29th May 2012
quotequote all
No problem reviving the thread, i'm still on the hunt for a sender as well! Just finished my body off rebuild so haven't really been looking too hard or even thinking about it (tbh i forgot it was fubar). Thats is until i took it for it's post rebuild MOT and after 10 miles it stopped working. Works fine for the first 10 or so miles then stops.smash

The Big G

854 posts

106 months

Tuesday 29th May 2012
quotequote all
There are 4 and 8 pulse senders for the early LT77 box, but they are not interchangeable. I really struggled to find a replacement for my V8s, and sent mine off to be refurbished, but that still didn't fix the problem. In the end I changed the system entirely to one reproduced by speedy cables. It has a new speedo in the dash, had the front printed the same as the old one with the old needle which takes an input from prop shaft bolts. So far so good. There was a group buy on them about a year and a half ago, I'll see if I can find the thread.

Edit for some links

Ant.'s replacement speedo solution
The solution fitted to a couple of V8s'

Edited by The Big G on Tuesday 29th May 21:24

Hoover.

5,913 posts

180 months

Wednesday 30th May 2012
quotequote all
If any one is desperate for a speedo.... I've got one to fit a pre cat dash (black face,black beezle, TVR logo, lcd milometer) , needle unfortuntly starts at 7 o'clock but designed to work of sensors as the Ant replacement group buy

davep

999 posts

222 months

Wednesday 30th May 2012
quotequote all
Barreti said:
I'm reviving this old thread to keep all LT77 speedo sensor information in the same thread.
I hope the OP is OK with this.

I'm hoping someone knows where I can get a speedo sensor for a pre-cat with the LT77 box and the sensor in the side of the box.

Both the links above refer to sensors on the diff not the gearbox.

I think mine is on the way out because the speedo has become really intermittent.
It will do nothing for 20 miles, then suddenly spring to life for 10 miles or so before going back to sleep.
I'll test the sender before buying a new one obviously but at this investigation stage I don't even know where to go should I need one.

Ta.
IanB
I don't know if it's any help or not but the spare LT77 speedo transducer that I have in the parts bin has the following label and part numbers:

Caerbont Automotive Inst Ltd 11/94, TES2404 - 2001, and 1194, Orange, 20 teeth drive wheel, with two pin (pin 2 Brown, 3 Yellow/Black) RISTS connector. Whether its a 4 or 8 pulse version I've yet to verify.

Rimmers sometimes do used ones. Mine was bought from Racetech Direct Parts.

Good luck.



Edited by davep on Wednesday 30th May 12:06

The Big G

854 posts

106 months

Wednesday 30th May 2012
quotequote all
davep said:
Whether its a 4 or 8 pulse version I've yet to verify.
I can't remember but one of these is almost impossible to source, hence the group buy of new speedo's with a different sender.


davep

999 posts

222 months

Wednesday 30th May 2012
quotequote all
If there's a pulse O/P count problem from the SD1 transducer/sender then this circuit should solve it for £20:

http://www.jaycarelectronics.co.uk/productView.asp...

Ant.

5,250 posts

219 months

Thursday 31st May 2012
quotequote all
davep said:
TES2404
Seem to remember that this means it is a 4 pulse, the 8 would be a 2408....

JamesK

2,122 posts

217 months

Friday 1st June 2012
quotequote all
Does anyone have any pictures of this sensor in situ? I've heard you need to drop the exhaust to get to it but was wondering if I may get enough access to visually check for anything really obvious?

bubblehead

Original Poster:

264 posts

131 months

Friday 1st June 2012
quotequote all
Best i've got but should give you an idea what your up against.


Barreti

6,535 posts

175 months

Monday 18th June 2012
quotequote all
Working on the car this weekend and I pulled off the speedo transducer (yes, you do have to drop the exhaust)

I tested it on and off the car and can't find a fault now, so I'm hoping it was just a problem with the connector which I cleaned and pinched the terminals etc.

Anyway, here is a picture of the writing on mine in case its any use to anyone.

Griffith Speedo Transducer - TES 2805 / 2001

JamesK

2,122 posts

217 months

Tuesday 19th June 2012
quotequote all
Nice one Ian. I haven't managed to get mine looked at yet and don't want to start trying to do it DIY as I want to drive it to Goodwood on Sunday week and am keen not to anger the God of sods law!! Probably try and get it to Dan Taylor or someone like that.

Hoping mine is something worked loose too - let us know whether yours is ok.

stevesprint

955 posts

117 months

Wednesday 19th December 2018
quotequote all
Can anyone confirm the colour of the signal wire Yellow/Black or the Brown?
Cheers, Merry Christmas
Steve

Griffo400

39 posts

63 months

Sunday 27th January
quotequote all
Hi Steve, this might be of help.....