60s GM Fan Posted January 13 Share Posted January 13 So this evening I decided to take the Toro out for a spin. In first gear she seems to slip a bit and then she started making a whining noise under acceleration but it would quiet down in second gear. When I got back she seems to whine even in neutral but not quite in park. She was fine just last week with no issues. Fluid seems topped off but perhaps a bit thin? Whats going on? Link to comment Share on other sites More sharing options...
60s GM Fan Posted January 13 Author Share Posted January 13 Follow up- based on receipts she had a full rebuild of her transmission in 2016. Fluid hasnt been changed since then. Link to comment Share on other sites More sharing options...
60s GM Fan Posted January 14 Author Share Posted January 14 Torque converter is failing. When the transmission was rebuilt in 2016 they reused the original one because the owner didnt want to pay 400 dollars for it... Link to comment Share on other sites More sharing options...
joe_padavano Posted January 14 Share Posted January 14 13 hours ago, 60s GM Fan said: Torque converter is failing. When the transmission was rebuilt in 2016 they reused the original one because the owner didnt want to pay 400 dollars for it... Of course that whining usually means bearing wear, which sends fine metallic particles throughout the trans. 1 Link to comment Share on other sites More sharing options...
60s GM Fan Posted January 14 Author Share Posted January 14 I'm hoping its not that badly damaged. It occured locally and I didnt drive her more than 3 miles before she went in for service. All speeds were 45 and below. Rather not have to spend 4-5k to rebuild a transmission thats already been rebuilt. Link to comment Share on other sites More sharing options...
Ronnie Posted January 14 Share Posted January 14 On 1/12/2024 at 10:25 PM, 60s GM Fan said: So this evening I decided to take the Toro out for a spin. In first gear she seems to slip a bit and then she started making a whining noise under acceleration but it would quiet down in second gear. When I got back she seems to whine even in neutral but not quite in park. She was fine just last week with no issues. Fluid seems topped off but perhaps a bit thin? Whats going on? Could be as simple as air in the system. Air will cause any hydraulic system to whine. With the engine idling, and your foot on the brake, slowly move the shifter from drive to reverse - reverse to drive repeatedly for several minutes. If air is the problem that will get it out. Don't think the the converter failing is the problem because converters don't know what gear the transmission is in and they don't go bad when not is use. Link to comment Share on other sites More sharing options...
avgwarhawk Posted January 14 Share Posted January 14 Not knowing how loud the whining noises are, my experience with GM transmission is there is always a bit of whine. Link to comment Share on other sites More sharing options...
60s GM Fan Posted January 15 Author Share Posted January 15 My shop said that the shutter and whine was very noticeable in first. Quiets down a bit in second. This just popped out of the blue and the fluid is full. It will even whine in park now. Link to comment Share on other sites More sharing options...
60s GM Fan Posted January 24 Author Share Posted January 24 Update. The transmission and torque converter were fine. The AC compressor clutch was completely shot and causing the noise. After a trans flush, etc she's all ready to go. Thanks for all the input! 2 Link to comment Share on other sites More sharing options...
EmTee Posted January 24 Share Posted January 24 Didn't you recently replace the A/C compressor? Link to comment Share on other sites More sharing options...
60s GM Fan Posted January 25 Author Share Posted January 25 No it was on the car and fried out last summer. Easy fix but I'm glad its not the transmission. The 59 needs a rebuild soon so spending 8k on trans rebuilds etc was not an option. 1 Link to comment Share on other sites More sharing options...
60s GM Fan Posted January 26 Author Share Posted January 26 (edited) Welp they didnt fully fix it. Still has a slight whine in first and doesnt seem as punchy. Any ideas? Fluid was switched with the filter. The whine is faint but still there. Edited January 26 by 60s GM Fan Type o (see edit history) Link to comment Share on other sites More sharing options...
60s GM Fan Posted January 26 Author Share Posted January 26 So shifting is fine. I even had her up to 90 on the highway. Occasional mild vibration but no other issues. Seems to shutter and slightly whine in first. Link to comment Share on other sites More sharing options...
EmTee Posted January 27 Share Posted January 27 Try removing the air cleaner and see whether the whine goes away. My Riviera 'moans' sometimes and it sounds like it's coming from the air cleaner housing. I think it's a Helmholtz resonance. 1 Link to comment Share on other sites More sharing options...
60s GM Fan Posted January 29 Author Share Posted January 29 Definitely the torque converter. The shop owner who I normally deal with has been out for a week and his staff havent been that great about passing along info. I ordered a rebuilt one from Florida Torque Converter which should be the direct replacement for the THM425. Should be here by next Monday and the car hopefully done in two weeks. 1 Link to comment Share on other sites More sharing options...
rocketraider Posted January 30 Share Posted January 30 Will the replacement be a switch-pitch as original? Torque converter failure worries me some because there's no telling how much debris got circulated thru the transmission. 1 Link to comment Share on other sites More sharing options...
60s GM Fan Posted January 30 Author Share Posted January 30 They list it as correct for the 66 Toro. The transmission shifts fine, but shutters mildly in first into second. Link to comment Share on other sites More sharing options...
joe_padavano Posted January 30 Share Posted January 30 31 minutes ago, 60s GM Fan said: They list it as correct for the 66 Toro. The transmission shifts fine, but shutters mildly in first into second. If they also list the same P/N as correct for a 1968 Toro, then it won't be correct for a 66. Might want to double check. Vendor application lists for Oldsmobiles are notoriously inaccurate. Link to comment Share on other sites More sharing options...
60s GM Fan Posted January 30 Author Share Posted January 30 Just in case this is in fact the wrong torque converter, what vendor do you suggest then? Link to comment Share on other sites More sharing options...
joe_padavano Posted January 31 Share Posted January 31 2 hours ago, 60s GM Fan said: Just in case this is in fact the wrong torque converter, what vendor do you suggest then? I got my switch pitch converter from Fatsco. 2 Link to comment Share on other sites More sharing options...
60s GM Fan Posted January 31 Author Share Posted January 31 You were right. I ordered the wrong one. Their product 34-2 with variable pitch was the correct one. I get the joy of shipping the incorrect part back for a loss but now I'll have the right one. Fatsco said I'd have to send my old one in for a rebuild but sadly I can't have the car sitting in the shop for weeks while they rebuild the old one. Link to comment Share on other sites More sharing options...
60s GM Fan Posted February 21 Author Share Posted February 21 Okay this saga is still ongoing. I have heard zip from the shop that has my car and the side note I've now heard as of today is that the owner is pulling the engine to replace the torque converter. Are you required to pull the whole engine/trans just to replace the torque converter? Seems excessive and it seems as if this shop has no clue wtf they're doing. Link to comment Share on other sites More sharing options...
rocketraider Posted February 21 Share Posted February 21 No. If you can provide the shop a copy of the appropriate section of the CSM, it will show them how to remove and replace the transmission and final drive. Are they aware of the drive chain? Ya better hope so. Link to comment Share on other sites More sharing options...
60s GM Fan Posted February 22 Author Share Posted February 22 I gave them both the shop manual and body manual for 66 and they said it didn't show the front wheel drive set up? Am I missing something? Link to comment Share on other sites More sharing options...
joe_padavano Posted February 22 Share Posted February 22 (edited) 1 hour ago, 60s GM Fan said: I gave them both the shop manual and body manual for 66 and they said it didn't show the front wheel drive set up? Am I missing something? The Toronado section is at the back of the 1966 Chassis Service Manual as an appendix. I have to be honest - if this shop couldn't find the Toro section in the CSM, I have significant doubt about their ability to find a problem in the car. 😲 Edited February 22 by joe_padavano (see edit history) 3 Link to comment Share on other sites More sharing options...
joe_padavano Posted February 22 Share Posted February 22 2 Link to comment Share on other sites More sharing options...
60s GM Fan Posted February 22 Author Share Posted February 22 They've figured it out and found the section in the manual. They've not done me wrong so far but they're no longer on my favorite list. Thanks for the help. I'd like to get this 66 back on the road ASAP. Link to comment Share on other sites More sharing options...
60s GM Fan Posted February 27 Author Share Posted February 27 It appears that the torque converter was at its failure point. It also damaged the output shaft teeth. If anyone has the right source for these please let me know. TH-425. Thanks. Link to comment Share on other sites More sharing options...
joe_padavano Posted February 28 Share Posted February 28 Be aware that your 66 has a switch-pitch TH425. These 1966-67 transmissions used a unique torque converter. Fatsco has them on an exchange basis. That damaged shaft is the stator shaft and fortunately it's common between the TH425 and TH400 (and also common between switch-pitch and non-switch-pitch transmissions) so that should be relatively easy to find. Original GM P/N is 8623177. The smaller shaft is the turbine shaft, and fortunately it does not appear to be damaged. This part IS unique to the switch-pitch transmissions. Link to comment Share on other sites More sharing options...
60s GM Fan Posted February 28 Author Share Posted February 28 Joe I believe you're correct. The Stator Shaft is damaged but the other is not. Fatsco for this component? I already have a switch pitch torque converter from Florida Torque Converter. Link to comment Share on other sites More sharing options...
60s GM Fan Posted February 28 Author Share Posted February 28 Fatsco doesn't have the Stator Shaft. Any suggestions are welcome. Link to comment Share on other sites More sharing options...
joe_padavano Posted February 28 Share Posted February 28 2 hours ago, 60s GM Fan said: Joe I believe you're correct. The Stator Shaft is damaged but the other is not. Fatsco for this component? I already have a switch pitch torque converter from Florida Torque Converter. Pretty much any shop that sells TH400 parts should be able to source that stator shaft. Link to comment Share on other sites More sharing options...
joe_padavano Posted February 28 Share Posted February 28 (edited) Sonax P/N 34910S-01 Edited February 28 by joe_padavano (see edit history) 1 Link to comment Share on other sites More sharing options...
60s GM Fan Posted March 1 Author Share Posted March 1 Sadly that part wont work. It doesnt have the grove towards the back like mine does. Any idea? Supposedly this is a one year only part? Link to comment Share on other sites More sharing options...
ourkid2000 Posted March 2 Share Posted March 2 Great picture though of that transmission! Would love to see more close ups of that thing. It's buried inside my '66 Toronado that it's really cool to see it out like that. I really hope this works out for you. 1 Link to comment Share on other sites More sharing options...
60s GM Fan Posted March 6 Author Share Posted March 6 Well I'm in luck. The stator shaft can be repaired. It'll be returned to the shop in a week. This part is absolutely unobtainable so if anyone here runs into the same situation...the only place you'll find one is in a parts car or to have one made from scratch. 1 Link to comment Share on other sites More sharing options...
60s GM Fan Posted March 20 Author Share Posted March 20 The 66 is fixed and working perfectly. If you're looking for a switch pitch torque converter FL Torque Converter makes a good one. Butter smooth with tons of torque! 3 Link to comment Share on other sites More sharing options...
EmTee Posted March 21 Share Posted March 21 Glad to hear that you're back on the road. Thanks for the switch-pitch converter tip! https://www.floridatorqueconverters.com/ 1 Link to comment Share on other sites More sharing options...
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