Rubythursday
Member
Could it be the selector incorrectly adjusted so its actually in 2 and not D?
Need help with a bw35
- Thread starter kokomoguy
- Start date
necpwa said:
Indeed it could, and that was my suggestion in my reply to the very first post, but I can only go by the info that comes back to the questions I ask, and he said that the linkage was correctly adjusted. Counting the notches on the selector arm on the lever on the box and then seeing where the lever in the car is positioned would prove the point, but I have assumed that this has been done, and is correct. But we should be starting again from the beginning, so there's still hope......... :wink:
The volvo has a rod selector. I have adjusted it because originally it would not always lock in park. I have tried moving the shift lever sligthly forward while in drive to be sure that it is in drive and it shifts to neutral. Currently the kickdown cable is free at the carb linkage and pushed in so there is no tension on the cable. I'll start tomorrow by adjusting the shift linkage again.
kokomoguy said:
My only thought with a rod linkage was the possibility that if the engine/transmission unit was able to move about on the mountings because they were soft or broken, then you could be selecting "D", but as you accelerate the gearbox moves and pulls the selector rod back into "2" without you knowing. To eliminate that possibility I was going to suggest just nudging the lever forward to see if it then picks up TOP. I see you were ahead of me on that one.........
Try with the adjustment again and see what happens. In the mean time I'll try and think of anything that's either been missed along the way, or something else that hasn't been thought of that could cause the loss of TOP alone.
While you're under there, have a look at the data plate on the side of the box, and note down the series number of that particular box and let me know.
kokomoguy said:
If you don't mind, run this test again, but this time, as carefully as you can, run the speed up to the point where the engine gets to the point where it's beginning to sound a bit overworked. I don't want you to rev it to excess, just to get as much speed out of the car as you can. (The best way to do this would be to run the test with the car going down a steep hill, that way you can increase the roadspeed, without actually overstressing the engine, although you would have to be listening very closely to actually hear the change in these conditions, but you should see whether it was in TOP when you took up the drive again.) This would be running with as little line pressure as possible due to the kickdown cable being disconnected, to see if there is a point at which the roadspeed is finally high enough to trigger the change into TOP.
I do have one other idea, but it really depends on what happens if you finally manage to get it to shift or not.
Having given some more thought as to what would be the result of the running the above test again, made me realise that you could reduce any risk to the transmission caused by running with the kickdown cable disconnected by doing the tests with the rear wheels off the ground. (As long as the car is still level, and well supported and chocked.) But thinking further to what has been done before, we know the Governor is working to some extent because the shift 1-2 at about the correct speed, and that speed is reduced to virtually zero by disconnecting the kickdown cable. So from that I would assume from that the Governor valve is free to move in the housing, but there is a weight that slides through the centre of the valve, and continues to increase governor pressure after the valve itself has reached full travel. If the shaft that has the weight on the end were sticking in the valve itself it could cause problems at higher speed, so giving the correct 1-2 shift, but delaying or stopping altogether the 2-3 shift. Conversely if the valve were free and the weight were still able to move that could compensate for the stuck valve. It's unusual in that they don't give many problems, and when they do they tend to either work, or not, rather than half-work as in your case. I think it's unlikely that both are stuck, but if you get to the stage of taking the governor off, you're going to see one way or the other.
So you can run the test again if you want, but I can now see a possible cause within the Governor that may make removing it and having a look worthwhile. Knowing the Series number of the gearbox may be useful as later governors can't be dismantled in the same way as earlier ones.
So you can run the test again if you want, but I can now see a possible cause within the Governor that may make removing it and having a look worthwhile. Knowing the Series number of the gearbox may be useful as later governors can't be dismantled in the same way as earlier ones.
The series on the box is 5002. I all else fails I have found another bw35 out of a 79 triumph tr7 about 4 hours from me for $75 and it has 57,000 mi on it. So if I have to get another one at least I think I found a good deal even if I have to use a few of my parts. I will pull the tail housing off as soon as I can and inspect the Governor valve.
That can't be the series number but it could be the sequential serial number. The series number will only be 4 characters if two of them are letters. I have listed for Volvo of that era 11EN, 13EN, and 325, 327 & 469.
The TR7 was never fitted with a 35 box, only a 65, so it won't be any good for you really.
The TR7 was never fitted with a 35 box, only a 65, so it won't be any good for you really.
If it's slipping in REVERSE then the first thing I'd do is check the rear band adjustment, but as that was one of the first things I asked, (Is REVERSE OK?) loss of TOP and REVERSE is normally the failure of the rear clutch, and it is possible that you lose TOP slightly before REVERSE because REVERSE operates at a slightly higher pressure so just about manages to operate the clutch. In most cases failure of the clutch is cause by failure of the seal. The box has to come out, and special installers are needed to refit the pistons and seals into the clutch drums.