PhilAndrews Posted October 22, 2023 Author Share Posted October 22, 2023 Went fuel up tonight. On the way home stopped in for milkshakes. Just because. Phil 2 Link to comment Share on other sites More sharing options...
PhilAndrews Posted October 22, 2023 Author Share Posted October 22, 2023 A foggy start today. Headed into town. Turned into a scorcher. Left early because it was just too hot. Good turnout though. Phil 4 Link to comment Share on other sites More sharing options...
PhilAndrews Posted October 27, 2023 Author Share Posted October 27, 2023 Missing some wheels right around now. Phil 1 Link to comment Share on other sites More sharing options...
PhilAndrews Posted October 27, 2023 Author Share Posted October 27, 2023 Oh wait, there they are. Back on and the ride is improved. The old ones were a bit hard with age. Much better! Phil 4 Link to comment Share on other sites More sharing options...
PhilAndrews Posted November 6, 2023 Author Share Posted November 6, 2023 Two daily driven Pontiacs in one photo. Rare sight! Phil 1 Link to comment Share on other sites More sharing options...
PhilAndrews Posted November 23, 2023 Author Share Posted November 23, 2023 Drove to the end of the old highway. This used to be a busy, thriving little town. It's all but gone now. Phil 3 Link to comment Share on other sites More sharing options...
PhilAndrews Posted November 29, 2023 Author Share Posted November 29, 2023 Oil and grease tonight. Makes quite a difference. Was rewarded with a pretty sunset on the way out playing Taxi for the kids. Phil 4 Link to comment Share on other sites More sharing options...
PhilAndrews Posted December 4, 2023 Author Share Posted December 4, 2023 (edited) I had an interesting experience with the car this afternoon. I went to town to buy some lights for the house. I approached a red light, slowed very slowly and crawled to a halt; I felt each downshift, including 3-2, which is not often the case, particularly with the transmission hot. Heading home the car decided to run very well, quieter than usual and real smooth. That was nice. It gave me time to think on the hydraulics again. I have a spare valve block- so I pulled my original one out and had a measure- the maximum depth from flush the 1-2 piston sits is 0.16", so with the throttle valve plug lifted out of it's bore that far I started moving the TV plug with off-center force on it (because the spring buckles slightly and pushes to one side), and discovered that about half way in the bore is adequately worn to allow the edge of the piston to get hung up solidly. That would cause the 1-2 shift to not occur and also a significant loss of oil via the exhaust port from the governor circuit. In true hydraulics fashion the corners of the slug are a sharp 90° which is excellent for keeping a bore clean and preventing any crud building up and jamming it. However, that edge comes out of the top of the bore it sits in and relies upon the smaller bore to hold it central. So, with that slight off-center it can jam. So, I carefully turned a chamfer on the bigger part of the piston- much less critical to operation than the small bore portion of the plug. Now, that chamfer guides the plug into the hole each time without getting stuck. I'm going to swap that out and see if it makes the slightest bit of difference... Phil Edited December 4, 2023 by PhilAndrews (see edit history) 2 Link to comment Share on other sites More sharing options...
EmTee Posted December 4, 2023 Share Posted December 4, 2023 Nice picture - and the dash looks great! 1 Link to comment Share on other sites More sharing options...
PhilAndrews Posted December 4, 2023 Author Share Posted December 4, 2023 Swapped the valve block out. We'll see how it plays ball. Phil 2 Link to comment Share on other sites More sharing options...
PhilAndrews Posted December 5, 2023 Author Share Posted December 5, 2023 Significant improvement. Under very light throttle at low speed it can sometimes still get hung up but under regular acceleration it changes well. So far. Phil 1 Link to comment Share on other sites More sharing options...
cevensky Posted December 5, 2023 Share Posted December 5, 2023 So fascinated by your amazing acumen for this stuff. At what point can I bring my hydramatic down for rebuild? What are the shop hours??? 😂 1 Link to comment Share on other sites More sharing options...
PhilAndrews Posted December 5, 2023 Author Share Posted December 5, 2023 11 minutes ago, cevensky said: So fascinated by your amazing acumen for this stuff. At what point can I bring my hydramatic down for rebuild? What are the shop hours??? 😂 Wish I still had a shop! But, if you need help I can certainly become the peanut gallery, for sure. Phil 2 Link to comment Share on other sites More sharing options...
PhilAndrews Posted December 13, 2023 Author Share Posted December 13, 2023 A week of driving in 40° and 80° weather has shown there is scope for improvement. Hot, particularly with heat soak after sitting switched off after being driven, it'll hang up. I think what might work will be to put the end block into the oven and get it nice and warm, put some blue on it and see where it makes witness marks upon moving the hydraulic pieces. Phil 1 Link to comment Share on other sites More sharing options...
51UKChieftan Posted December 15, 2023 Share Posted December 15, 2023 Hi Phil, What bulbs did you use in the dash? Joe Link to comment Share on other sites More sharing options...
PhilAndrews Posted December 15, 2023 Author Share Posted December 15, 2023 (edited) 28 minutes ago, 51UKChieftan said: Hi Phil, What bulbs did you use in the dash? Joe 5 element "ice blue" ba9s LED bulbs. I'm not sure if they're available in 6V. Edited December 15, 2023 by PhilAndrews (see edit history) Link to comment Share on other sites More sharing options...
PhilAndrews Posted December 17, 2023 Author Share Posted December 17, 2023 Just snagged a new old stock valve block for the transmission. That'll mean I can see about getting a sleeve machined for the current block and see if that fixes the issues also, as a viable spare. Phil 3 Link to comment Share on other sites More sharing options...
PhilAndrews Posted December 18, 2023 Author Share Posted December 18, 2023 Car came in useful for taxi service tonight. It carries the largest volume of passengers of all our vehicles. Loaded six up, we drove on into the sunset. 1 Link to comment Share on other sites More sharing options...
51UKChieftan Posted December 18, 2023 Share Posted December 18, 2023 On 12/15/2023 at 2:03 PM, PhilAndrews said: 5 element "ice blue" ba9s LED bulbs. I'm not sure if they're available in 6V. Thanks Phil, Good point about 6V, I keep forgetting this is a 6v system😖 Joe 1 Link to comment Share on other sites More sharing options...
PhilAndrews Posted December 19, 2023 Author Share Posted December 19, 2023 The clock was losing time decided being adjusted, so time for a service. On the bench, pinions oiled and then set the hairspring balance. Yup, that's easiest set up with an oscilloscope. Nice and even pulses, meaning the balance wheel is running evenly each side from rest. Keeping time on the bench, checked for problems. Running well. All back together and in the dash again. Tick tick tick. Phil 2 Link to comment Share on other sites More sharing options...
EmTee Posted December 19, 2023 Share Posted December 19, 2023 I need an O-scope! 1 Link to comment Share on other sites More sharing options...
EmTee Posted December 19, 2023 Share Posted December 19, 2023 6 minutes ago, PhilAndrews said: Yup, that's easiest set up with an oscilloscope. Now, if only there was a way to connect that to your Hydramatic... 1 Link to comment Share on other sites More sharing options...
Andy J Posted December 20, 2023 Share Posted December 20, 2023 Phil,I am amazed at the things you do to this car. I will try a lot of repairs,but there are some things that I just don't have the confidence to try.There is no way that I would go into that hydramatic. If I had a spare,I'd go into it. I'm going to be forced to learn because I want to do them myself. 1 Link to comment Share on other sites More sharing options...
PhilAndrews Posted December 20, 2023 Author Share Posted December 20, 2023 37 minutes ago, Andy J said: Phil,I am amazed at the things you do to this car. I will try a lot of repairs,but there are some things that I just don't have the confidence to try.There is no way that I would go into that hydramatic. If I had a spare,I'd go into it. I'm going to be forced to learn because I want to do them myself. Well, this one was broken and I figured I couldn't make it much worse! Definitely a learning experience. The manual does explain relatively well, but the nuances of operation are not well described and that's what's thrown me off track a good number of times. I should write a theory of operation for it... Phil 2 Link to comment Share on other sites More sharing options...
51UKChieftan Posted December 20, 2023 Share Posted December 20, 2023 12 hours ago, PhilAndrews said: Well, this one was broken and I figured I couldn't make it much worse! Definitely a learning experience. The manual does explain relatively well, but the nuances of operation are not well described and that's what's thrown me off track a good number of times. I should write a theory of operation for it... Phil I think you should re write the whole workshop manual!😀 Joe 2 1 Link to comment Share on other sites More sharing options...
PhilAndrews Posted December 20, 2023 Author Share Posted December 20, 2023 (edited) Well, the D51 has a lot of clever things going on, most of which are "improvement" upon beefing up the clutch packs to cope with the additional torque from bigger engines. A good portion is connected to the throttle valve control, which is why that is important to be adjusted correctly - difficult without the correct tool, which they fail to give dimensions for. Handy. But, at idle, the TV (throttle valve) is closed, which means that the overall pressure is low (40-50psi), the front pump creating said pressure and the reduction caused by the uppermost shuttle in the pressure regulator having no pressure behind it from the TV. The non-return ball seals shut and prevents line pressure being lost via the rear pump, which isn't moving if the vehicle isn't. Placing the selector in Dr should cause pressure via the 1-2 valve, which will be in the 1 position. That engages both planetary gearsets into reduction by clamping the bands down. Gently applying the throttle (enough to get to about 8 mph, 2nd gear) will leave the line pressure low and result in a very gentle shift from 1 to 2. By the time you've pressed in the throttle enough to get to 11-12 mph the line pressure is brought up by TV behind the regulator slug and a more positive engagement occurs for 3rd, and then 4th. Neither should be jarring but if the shift to 3 (and particularly 4) drop briefly to neutral during shifts the TV position is wrong and needs to be adjusted. The light-throttle low pressure is inadequate to get the box to shift 3 and 4 correctly. The TV pressure also pushes against each shift valve, assisting the springs which determine shift point. Light throttle means the governor pressure simply overcomes the spring; the TV pressure also regulates the compensator pressure (that boosts the pressure to the servos and at light throttle causes the shifts to engage gently, heavy throttle it clamps down hard for a positive, no slip change under heavy acceleration). The governor pressure has two outputs. Primarily, the small governor slug modulates the pressure to push against the shift springs directly in relationship to the speed of the vehicle; the other output opens up from nothing to full at about 7 mph or so and that is fed to the reverse blocking mechanism, which physically prevents reverse accidentally being engaged above that speed. Reverse also has a hack fix; the original incarnation simply had a latching pawl that engaged into the reverse planetary. However, the vehicle had to be at a full halt before it could be engaged otherwise it would grind horribly before engaging with a bang. The pawl was retained but a metal cone clutch was employed in addition, which meant it could slip and engage while the vehicle is moving. Pressure on a piston prevents the pawl from engaging with the engine running. Switched off, it will engage reverse if selected; with no pressure the large spring on the second servo engages 3rd gear reduction. The two ratios working against each other effectively lock the transmission solid, and provide a parking brake. The cone clutch doesn't work very well, so second line pressure hack engages when R is selected; the middle slug in the regulator recieves pressure behind it and that forces the regulator shut until about 120psi is achieved. This clamps it tightly enough not to slip on a sharp uphill incline, for instance. There's a few other niknaks in the valve block but they only work to provide the effects described above. Common fault I have found is that reverse blocking doesn't work because the passages that feed the piston get choked up with friction material debris as they have no flow through. Doing about 10 mph, in Lo you should be able to pull the shift lever toward you and gently ease down toward R. If you can get to the between point where the box finds neutral, your reverse lockout system is likely blocked. You shouldn't be able to move the shift lever past being fully engaged in Lo. If you find that your shift is harsh 3-2-1 (particularly 2-1) or it shifts 3-1-2-1, the TV slugs are getting stuck and need cleaning, also a symptom of using hydraulic oil that's too thin for a worn hydraulic system (Dexron, Mercon etc). Shifting 1-3-4 with a difficult 4th (occasionally getting 2 to engage after snapping the throttle shut, ditto 4th, with 3rd freewheeling at about 30mph off throttle and not shifting to 4th) is symptomatic of the 1-2 TV slug being worn and I've not found a 100% fix for that yet. Phil Edited December 20, 2023 by PhilAndrews (see edit history) 1 Link to comment Share on other sites More sharing options...
PhilAndrews Posted December 21, 2023 Author Share Posted December 21, 2023 Oooh. Brand new old stock valve block. Gummed up solid with 70 year old storage oil, so that's next on the plan, trying to figure how to free it up. Phil Link to comment Share on other sites More sharing options...
Bloo Posted December 21, 2023 Share Posted December 21, 2023 If it is truly gummed up, soak it in something, maybe acetone. Handle it gingerly. Don't polish anything. 1 Link to comment Share on other sites More sharing options...
PhilAndrews Posted December 21, 2023 Author Share Posted December 21, 2023 I jave a can of Berryman Chem Dip. Thinking of giving it a bath in that, though I was also going to see if heating it up a bit would free it up enough to get the pistons to slide out to be cleaned (probably in gasoline). Phil Link to comment Share on other sites More sharing options...
Bloo Posted December 21, 2023 Share Posted December 21, 2023 Yeah, berryman might do it. 1 Link to comment Share on other sites More sharing options...
PhilAndrews Posted December 21, 2023 Author Share Posted December 21, 2023 Soaking down now, so we'll see Link to comment Share on other sites More sharing options...
PhilAndrews Posted December 22, 2023 Author Share Posted December 22, 2023 Dismantling of the valve block shows it is indeed not NOS. It is, however a factory reman so all the wear items are new. Fire was employed to allow gentle removal of all moving parts. It's cleaned up nicely, time to reassemble it after dinner. Phil Link to comment Share on other sites More sharing options...
PhilAndrews Posted December 22, 2023 Author Share Posted December 22, 2023 I said get it completely stripped down, cleaned out. I'm glad I remember how it all goes together... The bores are perfect, so that's a good thing. Hopefully this one has another 100,000 miles in it. Modern oil should help prevent it wearing so badly also. Got it all back together and ready to go. Phil 1 Link to comment Share on other sites More sharing options...
EmTee Posted December 22, 2023 Share Posted December 22, 2023 Can't wait to hear the test drive result! Link to comment Share on other sites More sharing options...
PhilAndrews Posted December 22, 2023 Author Share Posted December 22, 2023 9 minutes ago, EmTee said: Can't wait to hear the test drive result! Well, that'll be the acid test for sure. It'll be spoiled by the fact I need to set my valve lash... Link to comment Share on other sites More sharing options...
Bloo Posted December 22, 2023 Share Posted December 22, 2023 Wash the valves with solvent of some sort, blow dry with compressed air, dunk in clean ATF and drop them in. Don't allow any shop rags within 100 feet. Knife-sharp edges on the valves are what make them not stick. Be careful about handling them too much. Good luck. I don't envy you on the valve adjustment. It would be nice if we all had 3 hands . 3 Link to comment Share on other sites More sharing options...
EmTee Posted December 22, 2023 Share Posted December 22, 2023 14 minutes ago, PhilAndrews said: It'll be spoiled by the fact I need to set my valve lash... Ah, just turn-up the radio... 2 Link to comment Share on other sites More sharing options...
PhilAndrews Posted December 22, 2023 Author Share Posted December 22, 2023 Yup. Followed the manual procedure. Tipping it sideways lets the valves fall out under their own weight. The smaller ones need a gentle flick of the wrist for the same to happen so those are all good. Phil 3 Link to comment Share on other sites More sharing options...
PhilAndrews Posted December 23, 2023 Author Share Posted December 23, 2023 2 1 Link to comment Share on other sites More sharing options...
EmTee Posted December 23, 2023 Share Posted December 23, 2023 That was fun -- thanks for the ride! Nice job on the valve body and the Pontiac runs great! 1 Link to comment Share on other sites More sharing options...
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