Overdrive operation

[David6214]

Can anyone give me any idea of the expected rev drop for an overdrive at a given speed?<br>
<br>
I have changed the gearbox and overdrive (together) on my latest sprint and it doesn't seem to drop the revs as quickly or as far as the other box and drive did. I wondered if there was something I could measure it against?<br>
<br>
Thanks

<p>1980 Inca Sprint<br>
1979 1850<br>
1978 Inca Sprint<br>
1978 1850<br>
1977 Sprint in bits<br>
1973 Mimosa Sprint<br>
& no more space</p><i></i>

[Carsreunited]

It should engage almost instantly, probably only 1 sec.<br>
<br>
Revs should drop by around 500-600rpm ish<br>
<br>
use <!--EZCODE LINK START--><a href="http://www.minthlamb.co.uk">www.minthlamb.co.uk</a><!--EZCODE LINK END--><br>
<br>
It has a gear indicator/speed function.<br>
<br>


<p></p><i></i>

[alun n]

The ratio drop of a J type is 25%.<br>
<br>
Slow engagement could mean low oil or a sticky solenoid...if you are lucky

<p></p><i></i>

[tinweevil]

http://www.mintylamb.co.uk/gearspeed. Pray for low oil.<br>
<br>
Julian

<p>1978 <!--EZCODE LINK START--><a href="http://www.triumphowners.com/704">Dolomite Sprint</a><!--EZCODE LINK END--> Blue, a bit tetley. - Current daily drive.<br>
1972 <!--EZCODE LINK START--><a href="http://www.triumphowners.com/754">Spitfire IV</a><!--EZCODE LINK END--> No name, in bits.<br>
1968 <!--EZCODE LINK START--><a href="http://www.triumphowners.com/705">GT6 II</a><!--EZCODE LINK END--> Little blue, nice!<br>
1973 <!--EZCODE LINK START--><a href="http://www.triumphowners.com/755">Dolomite Sprint</a><!--EZCODE LINK END--> VA41, seriously tetley.<br>
1980 <!--EZCODE LINK START--><a href="http://www.triumphowners.com/864">Dolomite 1500HL</a><!--EZCODE LINK END--> Orange, really quite tidy.</p><i></i>

[2F45T4U]

Richard put his O/D on as soon as we jumped on the M4 in Port Talbot. It didn't kick in until we got past Bristol! <!--EZCODE EMOTICON START :rollin --><img src=http://www.ezboard.com/images/emoticons/roll.gif ALT=":rollin"><!--EZCODE EMOTICON END-->

<p></p><i></i>

[Jon Tilson]

blocked filters and or dodgy electrics...<br>
<br>
Typcial of a car thats been unused recently. WHen mine come out of hibernation the overdrive is always the last thing to wake up...<br>
<br>
Jonners

<p></p><i></i>

[David6214]

Thanks guys.<br>
<br>
Oil is fine (drained and refilled yesterday when I dropped the box in) overdrive on this box can't have been used for at least 6 months. <br>
<br>
Rev drop is about right, so I'll leave it in case it wakes up like Jonners' does.<br>
<br>
Electrics may well be dodgy - the wiring diagrams were not that helpful, but I guess you can't really wire them wrong can you?

<p>1980 Inca Sprint<br>
1979 1850<br>
1978 Inca Sprint<br>
1978 1850<br>
1977 Sprint in bits<br>
1973 Mimosa Sprint<br>
& no more space</p><i></i>

[Jon Tilson]

you can short out the inhibitor, which is a crap idea and can leave o/d engaged in reverse, which will wreck it.<br>
It MUSTNT work in 1st and 2nd isnt a good idea really, although some people like it.<br>
Jonners

<p></p><i></i>

[David6214]

It goes in and out correctly, it doesn't function in first or second. its only the solenoid and swicth wires that I couldnt check on the diagrams. Solenoid goes to earth and the switch. <br>
<br>
The rest of the wiring is as it was in the car. <br>
<br>
Jonners, do you know which wire should go where?

<p>1980 Inca Sprint<br>
1979 1850 Going on ebay at 20:00<br>
1978 Inca Sprint<br>
1978 1850<br>
1977 Sprint in bits<br>
1973 Mimosa Sprint<br>
& no more space</p><i></i>

[Jon Tilson]

its as per the wiring diagram. It goes supply, inhibitor, stick switch, soleonoid. Same supply is used for reverse lights swithc and usually splits at the inhibitor IIRC. Supply wire is green, and is fed from a connector by the oil filter area, with a multiplug with a loop through for the starter. Stick loom is connected via bullets and the wire to the solenoid is usually yellow.<br>
<br>
Yours sounds like it works as its meant to.<br>
<br>
You just need all the support clips and it lasts thirty plus years...<br>
<br>
Jonners

<p></p><i></i>

[David6214]

Thanks Jonners

<p>1980 Inca Sprint<br>
1979 1850 Going on ebay at 20:00<br>
1978 Inca Sprint<br>
1978 1850<br>
1977 Sprint in bits<br>
1973 Mimosa Sprint<br>
& no more space</p><i></i>