hdj
Rover Rookie
Posts: 12
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Post by hdj on Nov 23, 2018 18:10:51 GMT
My P5B Coupe has gearbox problem and I would appreciate some advice. BW 35 when moving off from cold ,the gearbox will not chnage up from 1 st gear and only changes into 2 by moving gear stick to position 2. After say 5/10 mins and while occasional moving to D position the top gear will be selected and operation of gearbox will be fine from there on. This was tolerable until things took a turn for the worse. While in top gear and full opening of throttle ,to active kick down, the engine revs rose very sharply and I suspect drive was lost. From there on ,top gear was not selectable ,although other gears seem ok. I had recently replaced broken O ring on rear servo and new AFT-G fluid refilled box . Did notice quite a lot of ,what appeared to be grey ribbon(swarf), attached to the magnet. Many Thanks, Dave
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Post by harvey on Nov 23, 2018 18:42:01 GMT
So, have you lost TOP gear permanently? And if so Have you lost any other gears at the same time?
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hdj
Rover Rookie
Posts: 12
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Post by hdj on Nov 23, 2018 19:42:41 GMT
Hello Harvey, TOP has gone permanently, however all other forward gears and reverse are ok. Cheers, Dave
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Post by harvey on Nov 23, 2018 19:50:37 GMT
If all the other gears function properly, with no hint of slip at all, (and if the selector gets all postions including PARK),then if the 1-2 shift speed is at the correct speed, all it could be as far as I can think, is either the 2-3 shift valve stuck, which I've never seen, or the governor is sticking. Failure of any of the clutch packs causes loss of drive in more than one gear, or in the case of the rear band, loss of reverse and the loss of engine braking in "1", and failure of the front band will give a loss of SECOND gear.
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Post by lagain on Nov 23, 2018 20:43:44 GMT
How long have you had the car and do you know the mechanical history. It could be low fluid level. I was told many years ago, by a Borg Warner engineer, that to check the fluid level, do it after a run with the fluid hot, stop on level ground, turn off engine and immediately check the fluid level.
What fluid are you using, it should be Castrol TQF or similar to same specification, unless the box has been rebuilt and another fluid specified.
If you check the rod that the kickdown cable is fixed to, behind the carbs, the rod should go into a rubber bush. If that bush has crumbled away it will affect how the box operates.
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Post by eightofthem (Andy) on Nov 23, 2018 21:20:58 GMT
I would double check the fluid level, how much fluid did you add when the box was refilled?.
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hdj
Rover Rookie
Posts: 12
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Post by hdj on Nov 23, 2018 22:22:20 GMT
Thanks Harvey, I will check functions you have mentioned and see what transpires. Is there any virtue in removing sump for any visual inspection ie kick down valve for example. I have checked kick down cable externally to ensure its not sticking and its doesnt seem to be. I have checked fluid level as per manual and is correct I believe. I cant see this being the problem though cos it was sort of ok until the kick down incident. Many thanks for your advice.
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hdj
Rover Rookie
Posts: 12
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Post by hdj on Nov 23, 2018 22:29:04 GMT
Will check kick down bits and fluid is AFT-G. Top gear didnt engage until 10 mins after start?? Then all ok from there on. Cheers, Dave
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hdj
Rover Rookie
Posts: 12
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Post by hdj on Jul 30, 2019 15:59:08 GMT
1972 P5B coupe with P6 HComp engine.
I have fitted recon BW35 gearbox and recon torque converter and car drives well apart from a vibration from the engine/gearbox and I wondered if the torque converter is out of balance or could it be something else?? Its most noticeable when car is stationary and throttle is opened.
Any advice would be very helpful.
Cheers, Dave
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Post by harvey on Jul 30, 2019 16:13:00 GMT
The first thing you could try is marking the driveplate to the converter, then removing the 4 converter bolts which hold the converter to the driveplate and run the engine to see if the vibration disappears. Dont run it for very long like that or you risk the spigot on the converter seizing in the back of the crank. If it does get rid of the vibration then refit the converter to the plate in a different position and try again. You have 3 other positions apart from where it was originally.
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hdj
Rover Rookie
Posts: 12
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Post by hdj on Jul 30, 2019 16:32:16 GMT
Thanks Harvey, I'll give it a try. Cheers, Dave
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Post by enigmas on Jul 31, 2019 2:40:37 GMT
Not all recon torque convertors are rebalanced...some companies merely mark the cases then split and repair/replace whatever is required. The convertor cases are then rewelded together based on the marked positions. Due to this 'method' of repair the convertor can end up with a mild vibration (that both tends to irritate and is difficult to initially diagnose). Now...it's not worth guessing how I know this or found out!
If you purchase a replacement rebuilt convertor ask the builder/company to sign off on your purchase invoice/document that the convertor has been dynamically balanced as part of the rebuild process. If they refuse go elsewhere.
PS. From your comments your BW35 has seen a lot of service and is probably dirty internally. Clean both the valve body (remove, strip and refit)
* The goverrnor is most likely sticking as well...so remove the tailcone (can be done in situ) and clean it thoroughly. Also blow out the oil feed port to the governor when the valve body is removed. Any decent BW35 manual will show you this port at the rear of the trans within the oil pan at the back.
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Deleted
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Post by Deleted on Aug 22, 2019 8:04:29 GMT
Rather than start a new thread,I thought Id add this here. Im going to drop the sump om my BW35 to replace the gasket. Im pretty sure before I even start that I'll be wasting my time as so many people suggest leaks from the box when stood are inevitable,but can any one recommend what type/make of gasket would at least give me a fighting chance of a dry garage floor?.
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Post by enigmas on Aug 22, 2019 9:45:39 GMT
The transmission pans are made of pressed steel and over the years the (supposedly) flat mating surface where the pan seals against the alloy flange of the transmission becomes compromised. Over-torquing the cork gasket to address weeping/leaking surfaces doesn't help the issue either. Spend some time with a good flat (bastard) file, emery paper and a solid flat glass or steel plate and ensure the surfaces are completely flat and true. You shouldn't be able to slip a .005" feeler gauge between a truly flat pan surface at any point between the pan flange and the flat plate you're using. * BW35s don't have to leak ATF on your driveway.
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Deleted
Deleted Member
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Post by Deleted on Aug 22, 2019 21:28:09 GMT
Thanks for the reply,I believe there are now alternative materials available for the gaskets,but I'll do a bit of research. I have a large surface plate and a two foot long draw file in the workshop along with a tub or two of engineers blue.
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Post by enigmas on Aug 23, 2019 0:36:38 GMT
The original BW35 pan gasket material will work fine and be leak free if you get the surfaces truly flat. Transmission shops don’t do it because time is money (to them) and it might take you a couple of hours.
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Deleted
Deleted Member
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Post by Deleted on Aug 23, 2019 8:21:41 GMT
I suppose thats true. There seems to be an obsession to get things done quickly these days,I have a load of old hand tools that most mechanics these days would not now how to use. Scrapers for bearings (we used to call them rifflers) and draw files,engineers blue etc. I have an old copy of an Engineers manual/encyclopaedia with pages devoted to lapping cylinder heads and crankcases to blocks by hand. I know we have machinery to do a lot of these things now but I still think we've lost something along the way.
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Post by Brendan69 on Aug 23, 2019 8:39:24 GMT
Mine also drips too but I live with it and have an old long towel laid under the car to catch the drips. They are really minor TBH. I have however bought the " heavy duty " gasket for the BW35 sump pan which cost me £30 off ebay seller who does them. classepartsltd is his name on there.
Nice chap and seems to know his Rovers and their traits. Good luck. I have NOT done mine yet as its one of those jobs you always put off. LOL
Not trying to teach you to suck eggs but one top tip ive always applied when doing gearbox sump pan gaskets it to allow the fluid to drain out into a clean large measuring jug so you know exactly how much has come out so you can put exactly the same amount back in via the dipstick tube filler and then at least you will know you have not overfilled it and can just top up if required after the relevant checks hot/cold.
Cheers
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Post by lagain on Aug 26, 2019 18:39:17 GMT
The gasket usually gets the blame for leaks as it is at the lowest point and fluid drips off the sump. Before you replace the gasket give the gearbox a good clean and then pack kitchen towel on the edge above the sump and see if it collects any fluid. The fluid can come through the inhibitor switch, if that is the case remove the switch and coat the area where the four prongs are with a good coating of Araldite !
One of the best ways to stop the gearbox leaking is to use the car at least once a week, they do not like sitting. My sump does not leak, but fluid drips from the hole in the torque convertor housing, presumably the seal between the gearbox and engine.
I replace my gearbox fluid every 12000 miles, using the method suggested by Brendan, with Castrol TQF. I know that replacing the fluid is not in the service schedule, but that seems rather odd to me.
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Post by johnwp5bcoupe on Aug 26, 2019 20:50:42 GMT
I replace my gearbox fluid every 12000 miles, using the method suggested by Brendan, with Castrol TQF The ATF you use will depend on what is advised by the box rebuilder "if a recent rebuild"? mine is a old box and uses Ford M2C-33G
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Post by Brendan69 on Aug 27, 2019 10:06:57 GMT
I forgot to mention that during my method I use I repeat this sequence about 3-4 times over the space of a couple of days adding fresh fluid and after each measuring jug full removed and this way I know that pretty much all of the old fluid has been pushed out of the box and torque converter. A bit long winded yes but it works for me and no doubt many others too.
Cheers
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hdj
Rover Rookie
Posts: 12
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Post by hdj on Dec 24, 2019 0:12:01 GMT
Hi, I would like some help re my BW35 gearbox that has been reconditioned recently and unfortunately has bit of a problem when cold. It wont change up from first gear,although will do after say 5 mins of running?? Rather odd it works OK when warmed up. Any advice would be appreciated. Cheers, Dave
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Post by enigmas on Dec 24, 2019 2:29:48 GMT
The governor valve is most likely sticking. As the transmission warms up...gets to operating temperature the ATF thins a bit and the valve is able to shift.
Possible Causes: * Not all the assemblies/fluid channels were thoroughly cleaned during the dismantling/rebuild process.
* The torque convertor still retained dirty/contaminated ATF after the rebuild. Fluid needs to be pumped through it and out to waste in a catch can or similar before returning to the transmission.
Options. * Warm the engine and transmission thoroughly before driving. You might find it functions perfectly using this procedure.
* Pump out all the current ATF (when hot) by disconnecting the return line at the radiator. Idle & then switch off the engine when fluid flow starts to falter.
* Do the above several times after using the car on decent runs. This should clean up the fluid successively.
* Last Resort. Remove the gearbox tailcone, remove the governor and clean it thoroughly. Remove the trans pan, valve body and blow out the governor line (governor removed) with an air line.
This can be done with the transmission in the car. You'll have to remove the tunnel cover.
Good luck.
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Post by eightofthem (Andy) on Dec 24, 2019 9:31:58 GMT
Don't do ANY of the above.
Contact your transmission supplier / builder first
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Post by enigmas on Dec 24, 2019 10:45:51 GMT
Probably the question you need to ask based on Andy's sagely advice is... was it professionally rebuilt and by whom...a transmission shop or by an enthusiast? If it was rebuilt by a 'professional' at a transmission shop the trans should have a warranty unless you installed it and didn't check the convertor. Either way I don't believe it's a meltdown moment. Perhaps other's with keener insight may disagree! Good luck with your endeavours.
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