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TR5/TR250 Removing the Transmission on a TR250 - any tips?

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RobT

RobT

Jedi Warrior
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Well my TR250 has developed a "sticky clutch". I suspect its the throw-out bearing assembly catching on the sleve. I am in the process of rebuilding the hydraulics in the slim hope that the problem is there but have to believe a transmission-ectomy is in my near future.

I've done Hearald & Spitfire boxes before - nice and light they are - but the bigger TR box with the O/D is probably quite a job.

So are there any tips for doing this (it is a O/D box)? I plan to remove it from inside the car, with the seats out and tranny cover off etc. Is there any order the bell housing bolts should be removed? The rear of the motor jacked up? Any idea of the weight? Should I use a block-and-tackle to help support the weight?

Any advice, is of course, very much appreciated.

Thanks,

Rob.
 
Hi Rob,

The box/OD weighs no more than about 125 lbs. It's pretty easy to lift. I wouldn't want to carry one around a lot, but I don't think you'll need a block and tackle. A second person might be useful, but I've wrestled a few into place solo.

Yes, jack up the rear of the engine a bit to allow the box/OD to slide backward off the engine. A flat piece of wood can protect the sump, with the jack under that. Watch the throttle linkage behind the engine doesn't get fouled and bent.

I don't know of any specific order to flange bolt removal. The earlier cars have a stud at 12 o'clock position that really helps reinstalling, something for the front of the gearbox to hang on (other than the input shaft!) while you work a couple other bolts into place. I'm not sure if that stud was used on TR250, but I am pretty sure it wasn't on TR6.

The most likely thing causing your problem is a sheared taper pin in the cross shaft. That allows just a little play, just enough to cause sticking and other problems. You can check for it without removing the gearbox from the car. Just remove the slave cyl. pushrod, remove the dust cover fromt the bottom of the gearbox and slip a short piece of pipe over the lever to operate the clutch while closely watching the action inside the bellhousing. If there is a little movement of the lever before the fork starts to move, that's a broken pin.

By the way, if the TO bearing carrier *is* hanging up on the sleeve, I think Revington TR offers an upgraded bronze sleeve to address that problem.

Good luck!

Alan Myers
San Jose, Calif.
'62 TR4 CT17602L
 
Rob,

Don't be so hasty to pull the gearbox. Your gearbox may just be out of alignment. It's very important to get it properly aligned. I've had this problem & did NOT have a broken fork pin. Now it could be hanging up on a burr or something, but trying the alignment is well worth a try as you don't have to pull the gearbox. I think the 2 & 8 oclock positions are a larger diameter...moss sells dowels, but you should be able to use drill bits or bolts. You may have to open up the hole a bit as the gearbox holes tend to get mushroomed...good luck

Todd
 
Re: Removing the Transmission on a TR250 - any tip

I was able to remove an O/D transmission from my TR3A by myself. In fact I removed it from both my car and my parts car and installed one back into my car all in a day. The one tip I would have that I used (can't remember where I got it) is to remove both seats, then when you are ready to lift the tranny, make a sling out of heavy rope and "truss" the gear box with the rope. Then the rope sling can be tied over your shoulder. With one foot each where the seats use to be it was simple enough to lift it. I set the length of the sling such that I had to be sqatted down to start and I simply stood up to remove the gear box. That way I was lifting with my legs and not my back.

Now I have to admit I was 26 years old at the time, but it was not all the heavy when lifted that way.

Good luck.
 
Re: Removing the Transmission on a TR250 - any tip

I've taken the gearbox out of my TR6 a couple of times. The first time I did it, I planned to remove it from under the car. I got it to the floor under the car, then I got in a situation where I didn't have the jackstands high enough to get the tranny from under the car. The bell housing was too big and it was caught by segments of the frame when I tried to pull it to the side, front, or back. I ended up resituating it under it's normal position and pulled it up through the floor.

Needless to say, the next time I did it I brought it up through the car as well.

I did it by myself both times. I positioned a jack under it to help.
 
Many thanks for the helpful advice...

Thanks for the many tips. Sounds like pretty much the same proceedure as the Spit/Herald boxes I am used to, but with more care given the extra weight. Alan - I think the Revington replacement is probably the same as the "Gunst" throw-out kit TRF sells. I will install this even if it is a sheared taper pin. Seems like a sesnible upgrade.

Most jobs on the TR I quite enjoy, but this one I am not looking forward to.

Cheers,

Rob.
 
Re: Removing the Transmission on a TR250 - any tip

I have pulled the transmission out of my car a couple of times, and it needs it again because I too have a 'sticky clutch'. Just for additional room to work, I removed the steering wheel and E-brake lever also. This may not be necessary for the 250. I also disconnected the throttle linkage at the firewal, even though I believe there is enouogh slack in the linkage to handle the small amount of movement needed.

I don't fully trust jack stands and for some peace of mind, I added some additional supports for safety. The TR6 bell housing has 2 - 3/8" bolts at the ~ 5 & 7 pm position and I leave them loose until last to support the load. These are the first to go back also. There' supposed to be 3 - 5/16 studs ( although there was only one in mine) in the engine for the top centermost holes in the bell housing which also help with alignment and the load as you align everything.

BTW: The nuts to all bolts should be on the transmission side.

Not sure if it is necessary, but I used a center punch and marked the drive shaft/tranny companion flanges for refit.

I solicited my son to help remove the tranny and we had no trouble at all. I had more trouble sorting the bolts out after he kicked the bolt tray over with his size 12's.

I believe I will also upgrade to the bronze TO bearing carrier.
 
Re: Removing the Transmission on a TR250 - any tip

Thank Dugger. I know previously I have had to remove the E-break just to get the transmission cover off, but taking off the stearing wheel sounds like a good idea too and pretty easy - as there should only ever be one nut behind the wheel!.

Rob.
 
Re: Removing the Transmission on a TR250 - any tip

One thing I never hear anyone talk about is to replace the main shaft bronze bushing in the end of the crank, (let it soak in 40 wt oil overnight & clean off) I'm pretty sure there is one? Also, a $5 clutch align tool is very helpful in getting the clutch plate aligned as you bolt the cover on. Be careful not to nick the bushing as you install the tranny, although if the clutch is lined up you shouldn't have a problem.

Anyone, please correct me if I am wrong.

p.s. you wanna do a heavy tranny, try a 70's Land Rover Series truck with overdrive, did it solo, through the interior using an engine hoist. /ubbthreads/images/graemlins/blush.gif
 
Addendum to Sticky Clutch Issue

As I mentioned in my original post, the reason I believed that I needed to pull the transmission was that the clutch was sticking. I assumed this was something to do with the throw-out bearing mechanism but was going to rebuild the hydraulics first.

Well it turns out that the problem was with the master cylinder. I had replaced this over the winter during a full hydraulics rebuild (brakes & clutch), and sure enough the piston in the master cylinder was jamming and scoring the bore wall. I rebuilt the original master (hone and new kit) and put that in, and the clutch is fine again. Another case of poxy repo parts letting me down, but I was relieved not to have to pull the 'box.

Rob.
 
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