I posted this one on the Classic Parts section of this forum, but I have not gotten any responses. You would think they monitor the forum, specially if a sale can come out of it . I will try this section to see if I have better luck. I installed a 4 speed saginaw tranmission in my 1953 Chevy truck. The transmision has a boss at the bottom of the tailshaft that looks like it was used in the original car (Camaro?) for some sort of mount. The way the tranmission mounts to the 235 engine it looks like is pretty well mounted. Do you think I need to install the crossmember 79-505 that Classic Parts sells? Am I ok without it? Do I gain anything if I install this cross member? Thanks, Antonio 1953 3100
Not that I'd be able to answer your question, but I think a picture might be good. If they see what you have and look at the member your talking about, they might be able to help. If they can, they will!
Here is a photo, the circle points to the boss and the thread on the two holes. In the donor car the tranny was mounted on some sort of crossmember, I just wonder if it would be ok not to use a cross member for the truck since the engine mounts are pretty beefy at the bellhousing side and on the front of the engine. Thanks, Antonio
You know if it were me I would go ahead and put the crossmember in and this is why I say this. With the engine and transmission being only held in by motor mounts that allows for a lot of verticle tailshaft play when taking off and coming to a stop I would think. This will wear on your U-joints and your motor mounts. If you can buy a crossmember (and I wouldn't think they would be to terribly expensive) then I would. By the way the picture looks it wouldn't be any big deal at all to install and it would be there for nothing else but a peace of mind. That's just my two cents (or if you go by Ken's standard then 3 cents for inflation )
If you put a crossmember in be very careful to shim the mount to where there is no force pulling down on the transmission. The camaro had a side mounted engine so the only other mount needed was the mount on the transmission. The parts books actually call this the rear engine mount. On an engine with the rear mount on the bellhousing the third mount must not pull down the back of the trans with the bellhousing mounts holding the engine up or else the trans will be in a bind. Since the mounts are rubber you have some leeway but I'd still shim it. Be sure to have the crossmember mounted a little low to allow for shims because if it's too high it will hold up the rear of the trans and have it bound in the opposite direction. I have seen alot mounted this way and give no problem but we had a super modified with a ridged mounted engine and broke several reversers (trans with just straight drive and reverse) before we learned this lesson.
Evan's Right I'd say make up a crossmember to suit as wiggly tranny tailshaft will also cause the output bushing to wear and this means drips on the driveway and (in the older trannies) poor shifting due to internal pressure loss . Make up the X - member so you have 3/8" or so of clarance and then simply make up a bunch of thin shims and stuff 'em in until there's no gap but also no pre load . Simple & effective . I wish my '49 had a Dual Hydromatic tranny.....
I know "Patrick's" has done many Saginaw conversions for our old 'Bolts. They also sell a kit for it. I have spoken to them a couple of times and they are very helpful with technical questions, especially if you have EVER bought anything from them, although it is not required for their technical expertise. Give them a call and ask away about your cross-member questions. I am certain they will have the right answers for you as well as the guys in this forum. Andy
You must have a cross member. Just think about the load factors as the drive line moves and also when shifting. Would for one apply a lot of extra load on the transmission input shaft/pilot bearing. Also depending on other factors would be a heck of a load on the driveshaft which would end up almost being your rear support mount in this case. Do like everyone suggested take your time measure then weld in a cross member will also provide proper support for the engine mounts. They were more designed to handle a side to side load not a front to back load. A lot of vendors-(Including CP) have easy to install kits or just make up your own.
Oh boy do you need a crossmember, I remember the old Jags used to suspend the box from a bushing and if that ever broke your arm would get ripped through the floorpan if you held onto the gearshift when pulling away! you wont belive how much that tailshaft will move when you let the clutch out, please dont take a chance and not build one. ________ Subaru Xt
Some of you guys are much more knowledgeable than I am,but many many of the vehicles I've worked on over the years have not had a transmission cross member. The front motor mounts and the bellhousing mounts were sufficient to control all the torque you could gather.
While I would agree there is plenty of vehicles without a transmission cross member. I do not believe with a solid driveline and the weight of the transmissions in AD's you should try it. The engines also have more weight towards the bottom end area of the motors so the motor mounts are already loaded to a certain level. Is safer and also better in the long term to just weld one in.
! Crossmember ! This is so but , remember : even in those years / applications where Chevy decided to save .50 CENTS per unit by leaving out the tranny crossmember the tailshaft housing of the tranny always had the holes for a mount , drilled & tapped as they _ALWAYS_ used one on heavy duty applications and moving this heavy old truck around is heavy duty service and moreso if you're using a romping , stomping V-ate engine.... Be smart , install a crossmember ! . if nothing else , it'll tie the driveline and that long assed old tech Ladder typ frame all to-gether and provide significantly better handling & safety... -Nate
