amazon /p1800 overdrive question

[red122]

hi. i would like to convert my 4 speed amazon to overdrive using a p1800 box I have. Is it a straight swap bar the propshaft? Is there anything else I need to change ? I have the remote p1800 assembly but Im not sure whether to go with this or stick to the original amazon gearshift. Anybody done this switch ? if so anything i should be aware of

[nozamaman]

Apart from the shortend prop( about £40.00 to shorten and rebalance, you will need the switch to operate the o/d the orininal fits in the cowl behind the steering wheel opposite the indicator stalk these are hard to find, the wiring is straighforward but needs a relay in the circuit if you ring me on 023 92 381494 I can snail mail you the details.

[123GT-AMAZON]

i have done the switch and if your using the remote shift setup then im afraid you will need to modify your tunnel to get the box to fit then as above wire up the overdrive and use a short prop end , you may have that if it came with the gearbox ( from a p1800 ) slip that on the end of your old back end part of prop checking the U- JOINT you should after that have a job well done.

[940_Turbo]

P1800 prop with fit a 120, providing it is the right age as the centre bearing changed in '67

[Derek UK]

The 1800 used a fine toothed drive gear and matching speedo gear. This due to the instruments being Smiths rather than the VDO one in the Amazon.I don't know what effect this has on the Amazon speedo readings.
It's possible that one of the UK OD rebuilders can also supply to convert it to an Amazon style gear, but they seem to have much more interest in the J type OD. It can be supplied from the USA for a D OD so that it works with a 4.10 axle. Yellow sppedo drive gear. Cost is $75 + postage of about $20.
I also have an 1800 box and OD to be fitted so I'm interested in this too. I'll use the long lever I expect.

[940_Turbo]

You can't just stuff a yellow speedo drive into a p1800 gearbox; the drive flange in the gearbox has a much finer worm on it and it'll eat the coarser drive gear in just a few miles. Unless the drive sleeve is changed you're stuck with the fine drive out of the 1800.

[123GT-AMAZON]

yes the speedo cable will need to be used to suit but we have done a couple now and all seem fine one car a year later and another 5 years later

no problems at all the hard part is the tunnel and the prop but is worth it i will post some photos when im at car next and also of the prop end but basicly i undone the U-JOINT and switched it from that point using the small end onto the old backend and everything went ok my estate was easier than dads due to the splines my one slipt on the 66 amazon estate dads one is a year older i belive from memory and we had to play with it a bit more but we got it on in the end all ok lucky he had spare props so gained the right splined end to cater for it

[Derek UK]

Originally Posted by 940_Turbo

You can't just stuff a yellow speedo drive into a p1800 gearbox; the drive flange in the gearbox has a much finer worm on it and it'll eat the coarser drive gear in just a few miles. Unless the drive sleeve is changed you're stuck with the fine drive out of the 1800.

Yes, that is what I said in my post. Thanks for the comment Peter.

[Volvo_133]

I have had a p1800 box in my amazon, though i used the amazon lid and long gearstick as i preferred to leave the heating duct as is. I never noticed much difference with the speedo readings when comparing these boxes. My car is 1970, so would not have left the factory with odrive.
Now running with a rebuilt amazon box.
Speedo reads 27 mph, when my satnav shows 30 mph. I live with it, drive with caution and keep my fingers crossed.
Chris.