Wogden 13 Posted August 19, 2020 Share Posted August 19, 2020 A 40 Century came in to the shop today. New owner. Complaining that he can't use 1st/R after the car has been driven and is warmed up. 2nd and high work fine all the time. It appears that someone recently had the tranny out. So we drive it and it works fine. Go around the block a couple of times and then no low/reverse. Doesn't matter if the engine is running or not. If you wait for 20-30 minutes it releases and works fine. Am reluctant to pull the tranny as it will be cold and it will be working fine so I was hoping for some ideas on where to go with this first. We may open the floor up and remove the inspection cover (6 bolt tranny) to look in there when this is happening. Any ideas would be appreciated. Link to post Share on other sites
1939_Buick 361 Posted August 19, 2020 Share Posted August 19, 2020 May help Link to post Share on other sites
pont35cpe 585 Posted August 20, 2020 Share Posted August 20, 2020 Maybe the clutch needs adjusting. Link to post Share on other sites
neil morse 1,569 Posted August 20, 2020 Share Posted August 20, 2020 Having recently removed and rebuilt the transmission in my '41 Super (with a lot of help from my friends!), I'm trying to figure out what could possibly be going on with this Century. The most difficult aspect as far as diagnosis for me is the fact that it works fine when cold but no longer works when it's warmed up. None of the suggestions so far account for the fact that works fine when cold. I guess my first question would be: was it working okay before the transmission was removed by the previous owner? What was the reason for the previous transmission job? What was done? If you could find out who did the previous job and have the opportunity to talk to them, you might be able to get some answers to these important questions. Also, maybe a dumb question, but have you checked the fluid level in the transmission? Is it possible that something is overheating because the transmission oil level is down? Link to post Share on other sites
Wogden 13 Posted August 20, 2020 Author Share Posted August 20, 2020 All good points fellas and I thank you for the quick response. Fluid level is where it should be according to my friend who has looked at it yesterday. I am going up to the shop this morning to crawl under the Century and have a look at other things. As far as I know right now the owner has no history with the car having bought it just recently nor do I know if he has any ability to speak with the previous owner. There was a hint from my friend that this was an estate sale implying that the p/o may be deceased. I have had quite a few selector trannies apart before but can't quite understand this heat/friction issue locking out 1/R. Who knows at this point what someone has done with this tranny. Guess we get to play "Sherlock" here. Got to get a look inside first. Does anyone know if there is an inspection cover in the floor that can be removed to get access to the top of the tranny? We have to look at this when it is stuck and warm. If we take it out of the car it will be cool and working. Guess we could cut the floor but I hate to do that as this Buick is in great shape. Link to post Share on other sites
Daves1940Buick56S 488 Posted August 20, 2020 Share Posted August 20, 2020 Don't cut! There is a fairly large opening with the cover held on by 6 screws. Just lift up the carpet or mat and you will see it. Once open you can pull off the top of the trans. 1 Link to post Share on other sites
Wogden 13 Posted August 20, 2020 Author Share Posted August 20, 2020 Thanks Dave for the heads up. The owner took the car back last night so I did not accomplish much this morning. We are scheduling him back soon and then we will take a look. I will update this at that time. Also, I had thought this was a sedan but Bruce tells me that it is a convertible. Link to post Share on other sites
1939_Buick 361 Posted August 21, 2020 Share Posted August 21, 2020 On 8/20/2020 at 7:08 PM, Wogden said: Does anyone know if there is an inspection cover in the floor that can be removed to get access to the top of the tranny? We have to look at this when it is stuck and warm. If we take it out of the car it will be cool and working. Guess we could cut the floor but I hate to do that as this Buick is in great shape. Yes. Easier if you take the front seat out Image below is of a 1939 series 40 Special RHD. 1940 Century uses the same basic body shell. Century transmission has a 6 bolt cover Link to post Share on other sites
Wogden 13 Posted August 21, 2020 Author Share Posted August 21, 2020 Thanks for the pics. That is a lot bigger than I had expected. I can see why it is easier with the seat out. 1 Link to post Share on other sites
DonMicheletti 678 Posted August 21, 2020 Share Posted August 21, 2020 The Century transmission is much bigger and heavier. Link to post Share on other sites
Wogden 13 Posted August 22, 2020 Author Share Posted August 22, 2020 Don, I am familiar with the two trannies from past rebuilds. However, I was a little amazed at the size of the inspection hole in the floor of that Buick pic😀 Link to post Share on other sites
DonMicheletti 678 Posted August 22, 2020 Share Posted August 22, 2020 Having recently worked on a '41 Super, I was surprised to find that theyhad eliminated that very convenient cover - solid floor Link to post Share on other sites
Roadmaster71 71 Posted August 22, 2020 Share Posted August 22, 2020 Has anyone heard about someone making their own inspection cover for the 1941 cars? I was also surprised when I went searching for it in my ‘41 Roadmaster and could not find it. Very disappointed . I suspect they may have been thinking about retaining the integrity of the glued down sound deadening material. Link to post Share on other sites
critterpainter 43 Posted August 25, 2020 Share Posted August 25, 2020 Sounds like a bad rubber bushing or mal adjusted selector lever. When cold holds shaft holds lever in the low-reverse position. When hot the resistance was gone. The "neutral" position is between 2nd and 3rd normally, trans lever has to be lifted for neutral between low and reverse. another possibility is the shifting forks and neutral lever were assembled wrong. One check ball or spring overlooked will cause things not to work right. Bob (jr) at Bobs Automobilia has parts and knowledge on these large series transmission 805-434-2963 Link to post Share on other sites
Wogden 13 Posted August 25, 2020 Author Share Posted August 25, 2020 Good point on the adjustment Critter. I am hoping that it will be that simple of a fix. Wondering if any member has a shop manual for the 40 Century that show the detail of the shift linkages. This unit has been out of the car before and it may not have been reinstalled correctly with respect to the linkages/tension spring setup. Can someone attach a picture of this and the adjustment procedures? Link to post Share on other sites
1939_Buick 361 Posted August 26, 2020 Share Posted August 26, 2020 18 hours ago, Wogden said: Good point on the adjustment Critter. I am hoping that it will be that simple of a fix. Wondering if any member has a shop manual for the 40 Century that show the detail of the shift linkages. This unit has been out of the car before and it may not have been reinstalled correctly with respect to the linkages/tension spring setup. Can someone attach a picture of this and the adjustment procedures? Download the 1942 Buick shop manual. All of it section by section. The pdf link does not work. http://www.oldcarmanualproject.com/manuals/Buick/1942/Shop Manual/ It is very comprehensive and has information that can be used with all straight 8’s. It has more information than was included in older “Shop Manuals” before 1942-41 You want section 7 pages 201 to 216 Page 118-A below is from 1928-52 parts manual does not indicate which series. Has another page for 1941 to 52 Link to post Share on other sites
critterpainter 43 Posted August 26, 2020 Share Posted August 26, 2020 Thats the little trans for the Special and Super Link to post Share on other sites
Wogden 13 Posted October 4, 2020 Author Share Posted October 4, 2020 UPDATE finally got the Buick back in the shop. As it turned out the insulator for the lower control rod to the selector finger was worn out allowing just enough slop that it would interfere with 1st/R selection. The insulator sets on top of the steering mast right next to the engine. When heated by the engine it became softer providing just enough extra slop to interfere with proper gear selection. Replaced the rubber insulator with a 50 cent bushing and away she drove! Thanks for all the input fellas. Pretty basic simple fix. The owner was tickled to say the least. 1 Link to post Share on other sites
neil morse 1,569 Posted October 4, 2020 Share Posted October 4, 2020 On 8/24/2020 at 9:33 PM, critterpainter said: Sounds like a bad rubber bushing or mal adjusted selector lever. Wow, a big cigar for @critterpainter! You nailed it! Link to post Share on other sites
critterpainter 43 Posted October 4, 2020 Share Posted October 4, 2020 Lucky guess. I've seen it a few times. Buick bushings can be problematic Link to post Share on other sites
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