| Over
the years many MGBGTV8 enthusiasts have been puzzled over quite when overdrive
on third was discontinued because it is clear that cars with chassis numbers (or
Car Nos.) of up to around GD2D1 1175G and probably higher have overdrive on third
whereas some much earlier cars do not. The myth that overdrive on third was discontinued
early in the production run can be laid to rest - see V8NOTE368.
To try and identify the chassis number change point when the overdrive on third
gear was discontinued we are running a simple survey of members on the V8BB. The
results of information received from fellow members is set out in the table below.
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More
data needed around the change point which is thought to be around Car No. GD2D1
1180 G | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
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Comments
from members' online forms Dene Denny: Overdrive on third originally fitted and available today but I never use 3rd gear OD. (Teal Blue 0637) 190611 Jonathan Moulds: Gearbox was rebuilt 10 years ago and modified not to allow O/D on third. (Blaze 0815) (21.2.11) Richard Withers: I would prefer to have overdrive on third. (Aconite 1196) (10.11.10) Michael Benton: I would prefer not to have overdrive on third gear. (Bracken 0942) (22.10.10) Jonathan Moulds: Assume original gearbox is fitted? Overdrive has always performed faultlessly. I tend not to put foot down in 3rd O/D, though so as not to stress the box. However, I don't avoid accelerating right up to the red line in 4th O/D. (Bracken 0809) (17.8.10) Kent Brown: Originally Mirage but changed to Damask. Overdrive on third not fitted now or when new. (Damask 1021) (5.8.10) Paul Tebbett: Checking back with the first owner as to whether overdrive was fitted to third gear because when Paul purchased the car much later the overdrive on third had been disconnected but it is now working again. (Bracken 1152) (1.6.10) John Emery-Barker: Overdrive originally and still on the car. I have always driven MGbs with O/D third and found it usefu. (Teal Blue 0675) (6.4.10) David Knowles: No overdrive fitted originally or now. (Damask 1215) (24.3.10) Peter Mullen: Overdrive on third originally and still working. Peter says "never found the need to use 3rd OD". (Glacier White 1090) (26.1.10) Trond Jonassen: No overdrive on third originally or at present. (Brooklands Green 2747) (20.1.10) Andy Simpson: No overdrive on third originally or now. Andy adds "just had a full gearbox rebuild". (Damask 1282) (18.1.10) Chris Owen: A Factory MGBGTV8, originally Bracken now Connaught Green, fitted with overdrive on third gear and no problems so far. (Connaught Green 0769) (17.1.10) Rolf Wissing: No problem with the overdrive over the last two years and works fine. Two years ago the third gear broke and the gearbox was replaced. (Damask 0416) (29.12.09) Peter Head: Acquired the car in 1987 when the previous owner indicated that the gearbox had been rebuilt. A recent "engine out" experience revealed a date stamp on the gearbox casing, just forward of the O/D unit, as 22/2/74. As the vehicle was built May 74 I presume that the case is original but the internals were rebuilt. Subsequently the main shaft was found to have written on it in indelible ink "MGB V8". I suspect that this is a result of the rebuild referred to by the previous owner. The overdrive is a superb piece of kit, known in our household as the "embarrassment switch" due to the rapid acceleration available when overtaking, and the resultant embarrassment caused to, young bucks who don't want to be! (Citron 1693) (11.6.09) Alan Davies: Reports his early MGBGTV8 has overdrive on third gear. (5.5.09) Pete Thomas: Gearbox was re-built by Geoff Allen in 1993 and he confirmed that the car had the orignal isolator switch fitted and had never had overdrive on third. The car has such a wide torque band that an overdrive on third is not really required. (Citron 1232) (26.2.09) Terry Silke: The car was rebuilt when an an R380 gearbox was installed. I could never get used to the fact that there was overdrive on third.So when changed down car then popped into overdrive. (Teal Blue 0437) (20.2.09) Brian Osborn: Can't see any point - it's almost the same as top. (Red 1725 was Glacier White) (23.1.09) Andrew Rake: At last we have another report in the "yellow zone" in the production where overdrive on third was dropped. (Blaze 1170) (6.1.09) Ron Stevenson: No warranty work and no overdrive on third. (Glacier White 1360) (30.12.08) Ian Walker: My Healey has overdrive on third and it seems natural for the MG to have it also. Mine works fine and I treat it with respect. (Citron 0982) (19.12.08) Graeme Don: Documentation makes no mention of any change from warranty work. I treat overdrive as a fifth gear and I think it would be less useful on third gear - requiring it to be switched out during the gearchange using the same hand. (Damask 1465) (2.9.08) Michael Baker: I have had the car from 4 months/2,350 miles and do not believe any modifications have been made. Third overdrive would be nice, but no unreasonable difficulties. The car was rebodied as a V8 Roadster with a Heritage shell in 1998 and is now finished in Nightfire Red. (Aconite 1340) (2.9.08) Chris Yates: Good cross country gear. (Glacier White, now Leyland Yellow 0455) (19.8.08) Darren Ainsworth: No longer using the original box as I've fitted a 5-speed R380. Overdrive on 3rd felt unnecessary: the torque of the engine meant there was little difference from accelerating in 4th. (Aconite 0832) (1.8.08) Henk Warnaar: Very pleased with overdrive on third - no difficulties. (Dark Blue 0480). (8.6.08) Dennis Wharf: No modifications, so no warranty work. With so much torque, I hardly miss not having overdrive on third. (Blaze 1189) (8.5.08) Barrie Jones: Because of the close ratios on a V8 gearbox, overdrive third is virtually identical to non-overdrive fourth. They cancel one another out. It does not provide a useful gear between third and fourth unlike the 1800 MGB where it is a useful intermediate gear. (Glacier White 0672) (21.4.08) Roland Mueller: In 1992 the gearbox was reconditioned. Maybe it`s not the original one. I have only a bill from John Hill`s about £215. I was just out for the first drive in this year and I like it very much on our Swiss roads. No problems at all. See you in August in ZUG, on the Diamond Jubilee from the MG Club Switzerland - V8. (Brooklands Green 1074) (13.4.08) Trevor Jones: Provides a useful overtaking gear rather than changing up on short straights. (Harvest Gold 1277) (1.4.08) Martin Bentley: This was V8 programme car number 6, commissioned on 8/3/1973 and invoiced to BLMC Publicity, Longbridge. It is registered as HOH 919 L. Development Department ran the car for 1,141 miles. The late Geoff Allen sent me copies of the Development Department's report sheets showing speeds/acceleration in gears. It only shows overdrive speeds for Direct Top, 4th gear. The car was tested by Motorsport October 1973 and Autosport in December that year. I've owned the car since 1975 with overdrive only on 4th gear. I've covered over 400,000 miles and just completed a full rebuild for the third time in February 2008. The car continues its role of a development car with numerous extras - for example power steering fitted and more. The car has only ever had OD on 4th gear and to my knowledge has never had the facility to engage OD on third. I purchased the car when it had done 35,000 miles and the service records do not show that the overdrive unit had been replaced or removed from third during servicing. Peter Beadle's point (removing OD on third was what the Factory recommended the MG service agents did when a car came back with a faulty OD and had to be repaired) may well be correct for my V8, but I have no way of knowing whether OD was removed from 3rd gear. It is possible that this may have been done by BLMC prior to BLMC Publicity Department selling the car on. My view is the car didn't need overdrive on third gear, a view confirmed to me when Ron Gammons lent me his V8 that did have OD on third - it scarred the life out of me! Although HOH 919L is no longer standard, with quite a few modifications that I like to think of as improvements to make it more useable for today's traffic conditions, it is now in beautiful showroom condition and I continue to use it. (Blaze now Midnight Blue 0121). (25.3.08) John Webb: Still fitted with the original gearbox with overdrive on third gear (Glacier White 0639). (15.3.08) Kenneth Perry: I rarely use overdrive on third gear (Glacier White 0862). (7.2.08) Peter Booij: The original gearbox in Tundra 0850 was replaced a few years ago by the gearbox from Teal Blue 1944 (my first V8) which has no overdrive on 3rd. I still have the original gearbox of 0850 to be rebuilt. As the gearbox is valuable I have always avoided using overdrive on 3rd. (5.2.08) Robert Charlton: Yes I do have overdrive on third and fourth, the car was commissioned on the 28.11.73, mounted on line 29.11.73, finished 30.1.-73, dispatched 10.12.73 and first registered in August 1974. (Damask 1044) (3.12.07) Phil Foord: I do not know whether overdrive on third was fitted originally. (Damask 1647) (27.11.07) Ryan Shaw: Overdrive on third is useful, particularly around town and in traffic. (Damask 1132) (18.11.07) Andrew Bowden: Overdrive on third would be useful - I liked it on my Triumph 2000 many years ago. (Damask 1884) (28.10.07) Peter Price: My MGBGTV8, Glacier White 0411, had overdrive on third but unfortunately the gearbox broke and the replacement now only has overdrive on fourth. (27.10.07) Chris Yates: Overdrive on third was very useful when present on other V8s I have owned. (Harvest Gold 1518) (24.10.07) Dan Suter: I believe my car retains it's original gearbox. It has had overdrive on 3rd and 4th gear since I purchased it in 1984. Having read the warnings from the V8 Register, I have used OD in 3rd gear carefully. (Harvest Gold 0131, now Damask) (20.10.07) Anthony DeBella: I liked third overdrive on my four cylinder MGBGT but with the V8 fourth overdrive is basically for motorway use only. I do not miss the overdrive on third option much at all. (Damask 1379) (19.10.07) Robert Kerr: Overdrive on third is very useful on the open roads. Third/third OD is an excellent semi-auto gearshift. (Harvest Gold 0870, now Glacier White) (19.10.07) Dave Hewetson: From my Car No (1787), I believe overdrive on third was never fitted. (17.10.07) Franck Morand: Apparently overdrive on third is the original equipment on my car (Glacier White now Mirage 0158) and it is working perfectly. (17.10.07) John Gibbins: I only use overdrive in top gear, unless I forget. (10.10.07) Mike Dunlop: I like o/d on third. It's never given me any problems. (2.10.07) Ron Bryans: I never use overdrive on third. (6.9.07) Charlie Provis: Overdrive on third would be handy. (22.9.07) Don Carter: Unaware of warranty work modifications. I hold extensive records from 1973 when the car was first registered in the UK and it was subsequently shipped to NZ. I am wary of using overdrive in third, however it performs faultlessly. No service issues. Mike Price: Mine is GD2D1219G in Bronze Yellow. It did have overdrive on 3rd when I bought it in 1979. Unfortunately after a bit of spirited driving in the mid '80s, I managed to explode the gearbox. In fact the only useable pieces were the case and the mainshaft, the only parts that were unavailable at the time!! Even the thrusts were scrap - it was a real mess. And that was before I did naughtiness to the engine! I got an exchange gearbox from Ron Hopkinson at Derby for £500, with the later layshaft. Sadly, it had overdrive on top only - I was under the impression that the later layshaft cars were top overdrive only and the earlier layshaft cars were overdrive third and top. I still miss the overdrive on 3rd - it was ideal for queue-hopping, just dropping the engine revs a little, so when a gap appeared, a flick of the lever gave more revs and power for some demon overtaking. Don't do that these days of course - being older and wiser. Fat Chance! David Halliday: Do not know if any warranty work was done. I cannot confirm that overdrive was available on third from new, but it certainly has been in my ownership. Really overdrive on third gear seems to be of little use. No difficulties known. (10.9.07) Robin Macleod: My V8 was originally Teal Blue, now Black. (6.9.07) Kevin Hallsworth: Low mileage original untouched car. I have never really used overdrive in third. (4.9.07) Peter Jones: There is an MGBGTV8 for sale on eBay registration SWR 897 M which was first registered in April 1974. The seller claims it has overdrive on 3rd and 4th gears. I spoke to the seller of this car and he assured me that it did have overdrive on 3rd and 4th gears and said the colour is Citron and the Car Number is GD2D1 1159 G so it is getting close to 1200 mark where the change point might be. (22.8.07) Vincent Maenhaut: No records of any warranty work. By the way I'm not sure if it is the original gearbox so do not know if overdrive was available originally. However, the extensive history that I have - and 86k miles is believed to be genuine - does not mention any change of gearbox. (19.8.07) John Fry: Letter from the late Geoff Allen on 26th August 1990 said "Please find enclosed History and copy of Test Report of your V8 0124, which was one of the 10 works demonstrators all of which had HOH XXX L registration. numbers. These cars were checked by Rectification Department, run on the road for around 1,000 miles, passed to Developement for testing, then returned to Rectification for further repairs etc. They had gearboxes changed to O/D on top gear only during the Easter Weekend and modifications to the oil gauge pipes to take the supply from the pump, two modifications which were not on production cars until around car 1,000. They were used for Press Demo work and Photographic Sessions etc ". John adds his car was the actual Autocar Test car on 16th August 1973 with "overdrive on top gear" at the time of the test. Dave Wellings: Dealer service records show that the ‘gearbox’ was replaced at 15,000 miles and again at 30,000 miles. There is no mention of the overdrive in those records. I can only assume therefore that the third OD option was taken out at one of those changes. Bryan Shacklady: I have invoices dating back to the late 1970s and there is no suggestion that the car has had any modifications to its engine or gearbox, or any work on either. In fact, I was considering having the gearbox rebuilt. I was advised not to use the overdrive facility on third gear when I bought the car, and, other than one use to see that it was there, I have not done so. I can't imagine why one would need to use it with the amount of torque provided by the engine. Tim Bedford: This is a follow up posting as "after a bit of digging I have found this car had its overdrive gearbox changed on the 20th May 1981 so possibly it was originally fitted with 3rd overdrive? Just don't know? Gordon Hesketh-Jones: I recall what dear old Sid Hurrell of SAH Accessories in Leighton Buzzard told me about the TR3A gearbox which of course also used the Laycock O/D unit. Sid’s instruction was to NEVER use it on the road in normal driving – just to save it for racing starts. Sid prepared racing Triumphs on a semi-works basis and I seem to remember that on the official works rally team TR3As and TR4s, the plunger for 2nd gear was disabled for the same reason. Paul Smith: Indicated he had owned his V8 since 1978. Damask 1378 is by far the latest V8 we have seen with overdrive on third gear] (17.7.07) Steve Foldhazy: Commented he had owned his V8 since 1979 and it had overdrive only on top gear. [We are trying to clarify whether his records show whether the car had any warranty work which might have included the removal over overdrive on third] (17.7.07) Peter Berry: Have got third overdrive but don't use it very often. Never had any problems with the overdrive. (16.7.07) Daniel Heyer: I had the gearbox changed myself around five years ago and there was no third gear overdrive on the exchange box.. I do not feel overdrive on third gear is really necessary with all the power and torque of the engine. A Factory LSD would have been much more appreciated! I might add that I never quite dared to use the third gear OD as everybody kept telling me that this tends to be a weak spot. When the original gearbox broke (during a regularity, of course, and on the last day of a three day event...), I replaced it with the old gearbox of Andrew Harnor who told me that he destroyed his by overtaking a tram and switching to third gear OD under load. Crunch. (16.7.07) David Stonehouse: In 2006, I stripped the teeth off third gear when under hard acceleration in third overdrive. (16.7.07) Peter Macey: My gearbox has been rebuilt but the overdrive is original. I find overdrive on third gear very useful. Steve Bowley: The gearbox was changed early on under warranty but overdrive still remained on third gear. People do not believe the car has in effect 6 forward gears! (15.7.07) Victor Smith: One respondent commented that "I cannot see the usefullness of overdrive on third". It's a fair point if you have had an MGBGTV8 with overdrive on top and have not driven one with it on third gear. My view is that as I have always had overdrive on third gear since I got my MGBGTV8 in 1978, it has seemed a natural part of the car. I have a Volvo 940 SET Estate which has overdrive on only top so I have experienced both types. I find overdrive on third gear is very useful as both an intermediate gear between top and third and also a very useful way of accelerating as you simply operate the stalk switch at say 3,000rpm or so and the engine falls back 500rpm. Equally dropping out of third overdrive provides a convenient way of turning on more power for overtaking or when approaching a hill. But it is essential to develop a reflex routine of clicking OD off when you come down the gears and into second to avoid the unintended operation of the overdrive as you are accelerating in third gear at relatively low engine speeds. The high torque, which all V8 enthusiasts find one of the features which is part of the character of the MGBGTV8 model, can in those circumstances damage the overdrive. Unlike my Volvo, which was manufactured some 20 years after the V8, the overdrive switch on the MGBGTV8 does not automatically switch off when you select first, second or neutral. (15.7.07) Gavin Bailey: I can confirm - and it will be no surprise - that my MGBGTV8 Glacier White 0199 has overdrive on 3rd and 4th. When we rebuilt it last year the car seems to have had a replacement gearbox at some time but we have in fact replaced it with the gearbox from the early rubber bumper car which I acquired for parts and broke - that had the later remote with overdrive only on 4th. (15.7.07) Ron Morgan: I avoid overdrive on third knowing that it was discontinued later. (16.8.07) Chris Vernon: Mine jumps out of third gear anyway without overdrive. (16.8.07) |