| Author | Message | ||
     Brian Vogel Grand Master Username: guyslp Post Number: 399 Registered: 6-2009 |
One thing I noticed today when taking the maiden voyage in LRK37110 is that something's "not quite right" as far as the transmission goes. I will preface this with the fact that I found that the fluid level was a bit low (less than one quart) when the following presented themselves. I've since topped off the transmission and driven briefly, but there doesn't seem to be a substantial change. The engine does not appear to be a factor and is running far better than I had any reason to hope it would at this stage. When the car is cold, take off from a stop seems perfectly normal. The shift between first gear and second is particularly marked, while the shift between second and third is marked, it is less so. As the car warms up things seem to get weirder as far as starting from a dead stop. It's just painfully slow and the shift point is at a higher speed than I would have thought. This is also sometimes true as far as shift point from second to third than I might have expected. In third when cruising everything seems to be perfectly normal and the car is normally responsive. I seem to recall issues like this being tied to the vacuum shift modulator, but could be wrong. Any ideas as to what I need to delve into to start probing this once the car is back from getting its new exhaust installed? Brian | ||
| Geoff Wootton Prolific User Username: dounraey Post Number: 186 Registered: 5-2012 |
Hi Brian Congratulations. There is nothing like driving one of these cars - makes all the effort worthwhile. I had an issue with the modulator. The symptoms on my car were late upshifts with very little "slip" causing a noticable jolt on each change. The downshifts were ok. The cause was the rubber hose that connects to the modulator from the down pipe that runs from the inlet manifold. Sometimes these split, losing the vacuum although on my car the hose had simply stretched around it's circumference causing a sloppy fit. The upshifts were vastly improved on replacing it. Geoff | ||
| Geoff Wootton Prolific User Username: dounraey Post Number: 187 Registered: 5-2012 |
Hi Brian Another thing to check is that the kickdown switch has not stuck in the on position - just a thought. Geoff | ||
| Brian Vogel Grand Master Username: guyslp Post Number: 400 Registered: 6-2009 |
Geoff, Your description of "late upshifts with jolt" sound almost precisely like what I'm experiencing. Once I have the car back with its new (or at least partially new) exhaust this is the first thing I'll check. Brian, who really wants to be able to drive this car this summer | ||
| David Gore Moderator Username: david_gore Post Number: 1285 Registered: 4-2003 |
Brian, Check the O-ring at the top of the pick-up tube from the oil pan is installed or hasn't cracked. if the O-ring is not functional, air can be sucked into the fluid circuits in the transmission causing problems. | ||
| Richard Treacy Grand Master Username: richard_treacy Post Number: 2832 Registered: 4-2003 |
Surely simply a leaky, dislocated or split tube at the modulator. The tube is about 120mm long and is often split. RT. | ||
| Brian Vogel Grand Master Username: guyslp Post Number: 401 Registered: 6-2009 |
Thanks to all for your input. I can now explain the low fluid, at least, from a lapse of my own. When I had to remove the radiator for repair of course I had to undo the transmission cooler connections, resulting in a loss of fluid. I had forgotten to top up again right afterward. Right now the car's getting her new exhaust pipes (all the mufflers and catalytic converters were still almost like new) put on and I am several hundred miles away from her for the weekend. Brian | ||
| bobuk Unregistered guest Posted From: 92.40.253.185 |
Change the fluid and filter. A partly blocked filter will give these syptoms remove sump to get at filter fit new gasket (Message approved by david_gore) | ||
| Brian Vogel Grand Master Username: guyslp Post Number: 496 Registered: 6-2009 |
Just another quick follow up. LRK37110 is rather different in the way the vacuum hose is hooked up to the modulator. There is a very long steel vacuum line and the "soft line" between it and the nipple on the modulator is approximately 1.5 inches/4 cm long and held on by spring clips. On SRH33576 the soft line is quite a bit longer and, if memory serves, just pushes on at the modulator itself. I hesitate to proceed because I've often found these micro-sections of hosing to be far harder to replace than long ones and I'm doing this on my back under a car on jack stands. It would certainly be easy to slice off and the spring clips (which are not particularly substantial) could certainly be reused. I'd just like some input, perhaps from those who've been there and done that with this configuration, before moving forward. Brian | ||
| Brian Vogel Grand Master Username: guyslp Post Number: 498 Registered: 6-2009 |
Now I'm definitely in, "OK, now what?" mode. First, some photos for comparison.    Before the upper clip was removed from the little segment of hose the hose would not move. As soon as that one was off the hose along with the bottom clip could be turned on the modulator nipple with no difficulty, so I'd suspect this was where the leak was. However, as you can see, the nipple on the end of the vacuum line and the nipple on the modulator are effectively mated. My guess is that the hose segment was already in place on the modulator at install time and the upper clip had been placed on the hard line and then brought down to clamp the upper end of that segment once it was slid on to the vacuum nipple. I certainly could not duplicate this arrangement without removing the modulator, and I'm not sure how to do that of if it's even wise. I will probably end up taking the car to a local transmission shop we've used just to have everything looked over anyway. Now, however, I need to figure out what I really should do with regard to the latest issue I've created before driving it again. Is there a sealant that would be good to use here as a replacement for the hose segment? Should I try to get the modulator off and replicate the original arrangement? Or should I try to get the modulator off and do a hose arrangement much like that which was done on my other car? Suggestions welcome. Brian | ||
| Brian Vogel Grand Master Username: guyslp Post Number: 499 Registered: 6-2009 |
Well, after taking a break for a while I decided to soldier on today. Loosened the modulator retainer clip plus a retainer clip that held the vacuum line in place so that I could get some freedom of movement so that I could gently pull things apart. What I found is that the vacuum line and the modulator were "joined" by a small adapter that slipped into each, which can be seen half protruding in the first picture.   I did a hose arrangement between the steel vacuum line, which is flared almost precisely like a brake line on the end, and the adapter/nipple combination at the modulator using 7/32" ID fuel injector hose. Sadly, it didn't help at all. It is almost unbelievable how little "get up and go" the car has. With the accelerator fully depressed on a grade the car just does not gather speed anywhere near to the way it should. I don't believe this is an engine problem, as it seem to behave just like the engine in the Shadow II when not under load. This is a brief audio file of the engine being revved up, twice, after a short drive while sitting in the driveway. It was recorded with my phone resting near the firewall with the bonnet open, so things sound quite noisy. Other than that, though, everything about how the engine behaves when you hit the gas seems to be perfectly normal. Audio of Engine Sounds. I am going to take the car to my local GM transmission professional next week, as it should be serviced and checked over anyway. Is there anything else that's logical/obvious to others that could be causing this sort of behavior? [Shifts are still very late and rough, even after the tweaking with the modulator.] Brian | ||
| Patrick Lockyer. Grand Master Username: pat_lockyer Post Number: 855 Registered: 9-2004 |
Sprag clutch u/s. | ||
| Brian Vogel Grand Master Username: guyslp Post Number: 501 Registered: 6-2009 |
Patrick, Thanks. What do you mean by "u/s" - it's a shorthand I've not seen before. Also, if this is the issue, is it safe to drive the car to the shop without risk of completely destroying something? On the few occasions where I've managed to get her "up to speed" on the level or slightly downhill there is no difficulty in keeping her going at that point. I do not have fluid that's an odd color nor with a burnt smell. Brian, who's utterly out of his depth when it comes to transmissions and knows it | ||
| Paul Yorke Grand Master Username: paul_yorke Post Number: 1065 Registered: 6-2006 |
useless s**t! or more correctly . . .Unserviceable It does sound rough  | ||
| Brian Vogel Grand Master Username: guyslp Post Number: 502 Registered: 6-2009 |
Paul, The first thing that entered my mind was "upshift," which shows how unfamiliar I am (was) with "u/s". I'll leave it to the pros to give me a final verdict. I don't think anyone's going to know what's what until someone who knows these transmissions gets in there and pokes around. I would certainly hope that I don't have a major and unserviceable component failure in a car with 26K miles, even if that car has been sitting for relatively long periods. I've already sent an e-mail, including essentially the narrative from here and photos, to my transmission folks. A call will be placed in the morning. Brian, who will try to remain at least moderately sanguine, though not optimistic, about this situation unless an "official diagnosis" puts an end to that |
