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MG MGA - 5 Speed Right Angle Speedo Drive
|Has any one tried these right angle speedo drives when adapting the Sierra 5 speed gear boxes in the MGAs? |
looks to be a nice design and as Dave McCann pointed out to me , by using one of these drives you may avoid expensive recalibrating of the stock speedo.
|Chris,I can recomend the right angle drive.I have the 5 speed conversion with 3.9 MGB rear end.I have a Smiths speedometer which came from an MGB from the early 60,s with a 1040 revs per mile rating.I checked the speedo against a gps over a 1500 mile trip and came up with an 11% error on the odometer, so ordered an angle drive with a ratio of 1.11 to 1.|
When installed the speedometer odometer is right on but the needle reads fast by 4 mph at 60 mph.I can live with that.
The needle also does not waver like it did with the old set up so overall a good investment.
Speedograph is an excellent company to do business with,very helpfull and prompt service.
|A D Cox|
|Search the archive for "speedo angle" 5 Speed or similar terms and you will find a wealth of information on the angle drive as installed on an MGA along with lots of experiences.|
I did it and it works great with no modification of the tunnel or no new cable. Clearances are VERY tight for fitting the drive. (All described with pictures in the archive.
I have also ordered an angle drive from Speedograph. I used a 1:33 as the car will have a 1450 TPM speedo and a 3.9 differential. All of this is dependent on tire size and the ratio of the speedo drive gears inside the Type 9 gear box. I do not have mine on the road but plan to this summer. If you need assistance on the gearing, feel free to PM me. Did you ever find the wheels you wanted?
|Chris I agree with all the previous comments. Their service is fast and great. You need to calculate what angle drive ratio you want and they have a lot of choices. I found that with the standard 4.3 rear end, 185/65-15 tires and stock speedo I used their 1.0 to 1.4 ratio and it's perfect. No speedo flutter. The only problem is with tunnel clearance. I fixed this by cranking the tranny over as much as possible to the left and got about 1/4" clearance on the tunnel which is OK. No rattles. I also ordered a 4" longer speedo cable from them that fits easier.|
Andy 60 coupe
|Still working on gettin mine back together , I did not get the wheels and tires yet ...I'm leaning back towards Minilite / Panasport wheels. Still not sure what tire and size to use yet.|
|Chris, If you like the Minilite look, I would look for tires in the 195-70 size range as they will fit the wheel rim width better than 165-80 and still fit in the wheel well. They will cause your revs per mile to increase some because of the reduced diameter. All of this must be kept in mind when choosing the ratio of the right angle adaptor. The items that effect the accuracy of the speedo are: 1. Rear axle ratio, 2. Speedo drive gear ratio (in the transmission) and 3. the tire size. I am sure you know this but thought is worth mentioning, just in case. So don't buy that right angle adaptor until you decide on the tires.|
I have fitted one but not used it in anger yet. To make sure you clear the transmission tunnel you can machine off one corner which gives an extra 5mm clearance. I checked with Speedograph before doing this to check the drive would not be damaged.
|John, I only filed a little off the one corner which didn't make much difference. Your filing looks like it will make a difference. The photo attached shows how close my angle drive was before I moved the rear trans mount over another 1/4" to the left.|
Andy 60 Coupe
|Andy, maybe it's obvious and my brain just isn't working at the moment but I'm curious how you moved the transmission further to the left.|
|My clearance between the tunnel wall and the unit is identical to Andy Preston's. I had to cut a hole in the tunnel wall when fitting the unit with tunnel in place, otherwise it is geometrically impossible unless perhaps you go down John Francis' route; a point worth noting for anyone who intends to do this modification on an already assembled car.|
Unless I have missed something above, nobody has mentioned another great plus for this unit in that you are able to use the standard MGA cable, rather than one with a Jaeger fitting at one end and a Ford fitting at the other. The problem with the latter cable is that the Ford square drive is a different size cross section to the Jaeger. Therefore, they use an inner cable that is too small for the outer cable. This causes the inner cable to 'wind up' and cause the instrument wander that so many of us Type 9 users have suffered.
One year into use and my unit is running great.
Did you manage to use the original standard length speedo drive cable? My original drive cbale was replaced twice in about 1978 when the speedo bearing became seized (before I realised that it was seizing up). The new cables don't have the original grey or silvery gold finish on the outside sheath so would prefer to use the old cable but it looks as if it is only just long enough.
I found the original cable just long enough - nothing to spare, but it fitted! However, I believe there is a slightly longer cable available.
|Speedograph will supply a grey jacket cable at any length your require. I have a 72 inch cable that I plan to use with the five speed.|
|Andy B, the rear gearbox mounting bracket for the Type 9 Sierra box has transverse slotted holes that allows sideways movement. I just loosened the bolts and levered it over to the left, but now gearbox and driveshaft are slightly off line.|
For my speedo cable I had speedograph make me a new one which was 4" longer than the stock cable and it fits great and I have no speedo flutter in 2000 miles.
Andy P 60 coupe
|I have just received my Hi-Gear conversion kit and a recon. standard Ford type 9 gearbox and will install soon...reading this thread I now want to avoid recalibrating the speedo by installing a correcting speedograph angle drive. For those who have been through the machinations and calcs I have a standard 1960 1600 speedo ,a 4.3 rear and Dunlop 195/60R15 tyres..I calc that latter give me a rolling dia of 24.2 inch ( compared to the 185/65 tyres of Andy in previous note..his give a rolling dia of 24.5inch). Since the tyre size is the only difference on a relative basis with Andy's set up I if I used a speedograph with a ratio of 1.4 my speedo would run under by 1.2%..if so then negligible.|
Have I got it right??
|Andy..just got a little less lazy and did my own homework and read your post dated 10th April this year...and looks like 1:1.4 is correct for me .|
|A couple comments:|
Steve, I mounted the angle adapter on the trasmission with the tunnel in place from underneath. It is possible but not at all easy. All mountings were loose when installed and the snap ring was a real pain to place.
I used the standard MGA speedo cable and it fit fine. The angle adapter is VERY close to the tunnel but in 6000 miles no issues. A strain relief and support was installed on the transmission as advised in the instructions. (An early MGB cable will give you a couple extra inches in length if you need it.)
Neil, Get your installed TPM figure and compare with what is printed on your Speedo. Use that ratio to order the adapter.
I used the 6 wheel turns to get the turns of the speedo cable per mile (using formula below). It turned out to be 1040tpm which is a standard for an early MGB Jaeger speedo. That speedo works fine looks proper and is within 3% accurate. (I have 3.9 rear)
TPM= (1680 X T )/ R
T= Turns of speedo cable in 6 revolutions of the wheel.
Roll car on ground in straight line.
R= Center of hub to ground on mounted rear wheel.
Measure in inches.
|Jim...my speedo is a Jaeger SN6161/06 1440 ( taken from dial )which I believe was the standard 1960 1600 unit for 4.3 rear. Do the last four digits ie 1440 represent the TPM ?|
Glad it worked for you without cutting a hole. I already had a cable hole cut in the tunnel for the standard Type-9 arrangement. I simply enlarged it to make access easier, then put a foam-backed cover plate over it, secured with self tappers. The soft foam provides additional support to the unit and should cushion any vibration/knocking should the unit occasionally touch the tunnel - which it hasn't to date.
the length of LHD and RHD speedo cables are different, LHD is longer
Yes the number 1440 is the standard TPM speedo for an MGA with 4.3. I think almost all the Jaeger/Smiths speedos have the TPM number on the face. This is the original calibration with the then standard tires, etc.
MGB and other speedos have lots of different TPM considering their different transmissions and overdrive, etc. Check the TPM carefully if using one.
|Gearbox ratios and overdrives should not have any effect on speedos, the cable drive gear is at the rear of the gearbox or overdrive and only measures propellor shaft revolutions.|
Rear axle ratio and tyre size are what matters.
|M F Anderson|
|Mick...dont follow that one ...as it means if I dont change anything else ( ie tyres and rear 4.3 ) then I dont need to recalibrate my speedo when I change to the Type 9 from the MGA standard gearbox since the shaft moves the same ......and everything I have read tells me I do!!!|
You are mixing two things. I was talking of gearbox and overdrive ratios being changed, as that was what the previous post said. What I said is correct, the speedo drive gear only counts propeller shaft turns. A change of gearbox or overdrive ratios has no effect.
What you are talking about is the speedo gear in the Type 9 gearbox. It is different from the MGA gearbox speedo gear, so you have to compensate for that.
|M F Anderson|
|Mick..my understanding is that the speedo take-off runs at a constant ratio to the propellor shaft rpm but that this ratio varies between gearboxes ( ie ratio is different between standard mga to type 9) but obviously the ratio does not alter with gear changes within any box....think we are on the same song sheet...|
|Neil, I think you've got it right. The only difference between my car and yours is the tires and they are very close, so the 1:1.4 should be the correct one for you based on my calcs posted on April 10, this year.|
|Andy..thanks for the confirmation re the ratio...and what a lovely company Speedograph is!! I bought a 1:1 ratio angle drive with the conversion kit from Hi-Gear ( did not know you could get others until reading this thread ). I contacted Speedograph and cheekily asked if they would replace with a 1:1.4 unit if I paid the postage to and from Oz plus handling etc.. To my delight they did and so exchange is underway at a very reasonable cost. I also noticed that their guy ( Tim ) dealing with the issue was communicating with me at 10pm uk time on a Friday night. Looks like they still know the meaning of great service in parts of Blighty ...|
|Having followed this thread I ordered a right angle drive for the restoration of my 1957 Coupe. Like the rest of you I have been impressed both by Speedograph Richfield and the quality of the right angle drive but have had the same problems with clearance of the gearbox tunnel.|
Trying it out in the currently incomplete car led me to think about inverting the drive so that it is 'underslung'. I have since sent the unit back to Speedograph Richfield and discussed it with them. They reckon it should be a solution to the clearance problem and are cutting suitable gears.
It now remains to be seen how it fits in the car..... and how it works, although I envisage no problems with the latter.
I'll report again when the drive is installed.
|A F Enticknap|
|They have been so lovely that they have still not replaced my unit that failed within the first drive because the input cable for the unit split from its gear wheel. Now seven weeks and counting....|
|Hi guys, |
I got my right angle adaptor from Speedy Cables. They calibrated and restored my speedo (and dual gauge), sourced a speedo cable and provided the right angle adaptor matched to the ratio of the speedo (as there is a 1:1 and a 1:1.4 version. Very pleased with them.
This thread was discussed between 04/12/2009 and 07/12/2010
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