A lot of confusion exists since for the non synchro first transmissions there is a numerical difference from the od to nonod speedometer output. Mg mgb technical blue label od speedo gear in black label i am trying to correct my speedometer reading. Early mgb overdrive reference photos and description of the overdrive system on early mgbs. These rare overdrive units are now hard to find and fairly expensive to install. The overdrive should always be disassembled and carefully inspected before installation onto the transmission. It has synchromeshed gears on 234 and the overdrive has a wet clutch arrangement. Find and shop for gearbox overdrive 4 syncro gearbox products online at everyday low prices at brown and gammons. What is the difference between the early black label, and the later, blue label overdrives. Overdrive transmissions reference the mg experience.
Tranny fluid recommendation for vintage mgb woverdrive. I have a black label od attached to a 1040 tpm speedo that reads very high. Successful test of overdrive after swapping a non overdrive laygear 1969 into a overdrive box 1974 black label. There were three types of lh od for the mgb chromebumper 4cylinders cars had one with a black but see below laycock label, 4cylinder rubberbumper cars had one with a blue label with a different speedo drive ratio. Download mgb pdf, manual, mg mgb mgb gt 19621977, mg, mgb gt. Trf mgb and mgbgt parts overdrive electricals horn. Early mgb nonoverdrive gearbox uses the shortest of the three mgb propshafts 30 inches. This car is a lot of fun to drive but life has stepped in and it needs a new driver who will complete the job or just drive it every day. It was announced and its details first published on 19 september 1962.
Mg mgb technical overdrive not engaging correctly bbs discussion. Mga mgb mgc 3 synchro non overdrive gearbox 3 hole. Ensure it engages and disengages smoothly, but dont dismiss a car with misbehaving overdrive poor electrical connections or a low oil level are the most likely causes for nonoperation. Od operates in 4th gear only in units made from february 1977 onward. Mineral blue exterior with black interiorlight blue piping. Overdrive rakuten overdrive borrow ebooks, audiobooks, and videos from thousands of public libraries worldwide. Overdrives were fitted to less than 20% of all mgbs. The r stands for research, a method of determining the knockresistance of a give fuel formula, under ideal conditions.
Mgb 5 speed conversion sports car craftsmen sports car. Unfollow mgb overdrive to stop getting updates on your ebay feed. They are interchangeable, but the speedometer drives differ in that the early ones had 1280 tpm while the later had tpm. The overdrive unit was engaged by a toggle switch on the dashboard. It was originally from out west and had a very solid body. You need pay the return fee by yourself if you want to return the item without any quality issues.
Mg mgb technical overdrive not engaging correctly while returning from a day out yesterday and traveling at approx 65mph i tried to engage overdrive, the result was what i can only describe as the classic learner problem of kangaroo petrol. It is easy to see if an early mgb has this as there will be two holes drilled in the boot floor, which are used to mount the strap. You can refer to the welded rear mount in the previous article gt303 to see what may have to be done to the mga frame to mount this gearbox. The switch was moved to the top of the gearshift knob in 1977. With stock of over 50,000 lines in a purpose built distribution centre, we manufacture and distribute classic british car parts to both trade and retail customers worldwide. You certainly cant get away with removing the oil pump as that is operating all the time the car is moving and supplying oil via a lowpressure valve to many parts of the od for lubrication.
Mg mgb technical overdrive questions bbs discussion. Blue mg mgb classic cars for sale used cars on oodle. Sub harnesses for overdrive wiring are listed below under wiring. During the design stage of the mgb a choice was made to have a 4speed transmission, or alternatively a 4speed transmission complemented by an overdrive. Join millions of people using oodle to find unique used cars for sale, certified preowned car listings, and new car classifieds.
John twist explains how the overdrive circuits operate. Laycock overdrive was only ever an option during the mgbs chromebumper era, but can transform the cars usability. Mgb accessories flyer akd2079 1062 pdf an interesting early accessories brochure for the mgb. This is my 3 synchro overdrive gearbox that fits the 5 bearing engine. Check the fine wire mesh filter for drainage and fit a new gasket cover before replacing.
Unscrew the square cover and withdraw the solenoid and check the o rings are in good condition. Lately it has been going into overdrive after activating the switch, but it kicks out and causes the car to sputter between the overdrive and 4th gear. Arguably britains bestloved sports car, the mgb was launched in roadster form in. This book represents the collected knowledge of many mgb experts and allows problems to be identified and assessed quickly, and then. When changing your gearbox oil drain the overdrive unit and clean the magnetic filter element under the rectangular sump cover. This car has a 4spd manual with electronic overdrive. On 6264 cars the manual switch is wired back to the ignition switch. Here are a few comments about installing the early mgb dtype overdrive gearbox in the mga. These were only bonded on the later blue label overdrive units, instead of being riveted. Successful test of overdrive after swapping a nonoverdrive laygear 1969 into a overdrive box 1974 black label. Original overdrive transmission had 34 of the teeth broken off of 1st gear. I looked under the car and there are several wires.
And my blue mg is very hard to start at this point i know you do. Oct 12, 20 successful test of overdrive after swapping a non overdrive laygear 1969 into a overdrive box 1974 black label. This gt is a great everyday car which can be enjoyed all year round. I was reading an article in an old classic motorsports magazine it mentioned straight shift levers were used with overdrive transmissions. Overview on overdrive mgb by john twist, university motors ltd. This is surprising since as an optional extra overdrive on a 3synchro car cost about. Pretty sure the late mga double flange propshaft is a different length than any of the mgb units, because neither moss nor victoria british have a part number for it. The original was a six page brochure that folded twice.
All models of car have their own common faults and foibles as well as the general ills that can afflict all cars. Mg mgb technical blue label od speedo gear in black label. Speedometer driven gear on removable drive housing is red with 20 teeth 9. I sold my 1974 mgb roadster a couple of years ago, and missed it so much. The overdrive is activated by the flick of a switch on top of the gearshift. This coveted option adds a fifth gear, lowering the.
Beautiful restored 1967 mgb roadster for sale duration. Mg parts spares and accessories are available for mg t series ta, mg tb, mg tc, mg td, mg tf, magnette, mga, twin cam, mgb, mgbgt, mgc, mgc gt, mg midget, sprite and other mg models from british car spares company lbcarco. From 197412 through 1980 all rubber bumper cars it was changed to tpm. This coveted option adds a fifth gear, lowering the engine rpm to about 3000 at 70 mph. My mechanic says it isnt the electric switch but a part in the transmission and he says to. This mg has had some extensive restoration and the work has been photographed through various stages, copies of which are available. The mgb is a twodoor sports car manufactured and marketed from 1962 until 1980 by the british motor corporation bmc, later the austinmorris division of british leyland, as a fourcylinder, softtop sports car. Mg mgb the mgb is a twodoor sports car manufactured and marketed by mg cars and its successors as a fourcylinder, softtop roadster 19621980. Four gear with overdrive, convertible fabric top, tonneau cover, top boot cover, shop manuals, restoration book. The car is a 72 roadster albeit with a 7374 engine and as far as i can remember its a blue label type od. The gearbox is filled with castrol 2050 and the last time i looked was full. There were three different types of overdrive transmissions fitted to the mgb.
How does on tell if an mgb has overdrive hi i was trying to figure out the dash layout and there is a push button switch in the upper left hand side, it has a small red lens by it. A description of the vacuum switch, its component parts and its calibration can be found here. Some of these techniques offered here are rather drastic and are undertaken at your own risk. The mgb is a twodoor sports car manufactured and marketed from 1962 until 1980 by the. The chicagoland mg club cannot accept any responsibility for injury, loss, or damage incurred by any of these methods.
Mgb 50 blenheim palace 23rd september 2012 duration. I hate the idea of running motor oil in this tranny. Mgb overdrive for sale in uk 14 used mgb overdrives. Mg mgb 1976 v8 3500cc overdrive midnight blue very good conditionvideo. Overdrive dtype to 67 overdrive relay location, with vacuum switch below, image from ste brown, west yorkshire, uk. All usa spec mgb s from 1968 through 1974 used 1280 tpm transmissions and speedometers. Pearline has been in my extended family since she landed in the states almost 50yrs ago. Mgbs built prior to 1976 had overdrive as an optional extra and many cars were sold without this option. Bench test the overdrive transmission prior to installation.
The overdrive transmission would reduce the engine speed by approximately 8 per. Find blue mg mgb classic cars for sale on oodle classifieds. Tranny fluid recommendation for vintage mgb woverdrive bob. This book represents the collected knowledge of many mgb experts and allows problems to be identified and assessed quickly, and then to be dealt with in the most appropriate way. The interior features of an early mgb 1963 mgb features. Mgb overdrive gearbox for sale in uk view 58 bargains. All mgbs desperately need an overdriven top gear for highway driving, but unfortunately, the now pricey overdrive option was only installed on about 10% of usbound mgbs. Im in the process of resurrecting my fiances 1968 mgb.