| Author | Message | ||
     Benoit Leus Prolific User Username: benoitleus Post Number: 194 Registered: 6-2009 |
Lately, I've noticed that my '79 Shadow is leaking transmission fluid. If left standing for a few weeks, a small puddle will have formed under the car. It seems to be coming from the front of the gearbox, where it mates with the engine. What could cause this and can I to remove the transmission myself (I do not have a hydraulic ramp). Also, when accelerating hard the upshift between 1st and 2nd is a bit jerky. When accelerating normally or releasing the throttle a bit, the upshift is smooth. The upshift from 2nd to 3rd is always smooth. The transmission fluid and filter is changed every 2 years. Benoit | ||
| Richard Treacy Grand Master Username: richard_treacy Post Number: 3188 Registered: 4-2003 |
Your transmission is leaking at the front seal. It will need a new front seal and to have the torque converter neck either machined, sleeved or replaced. Simply replacing the seal may buy a few months only. Sure, you can do it all yourself, but unless it is a trophy you are after. It is best done by an experienced professional shop, and skimping by solving the leak alone has to be a folly. I have done a few myself, but with this particular transmission it makes no economic sense. If any of my TH400/3L80 transmissions leak I figure it is a sign of more to come and have it fully overhauled. In other words, at the first sign of leakage other than the oil pan I simply have the converter and transmission overhauled rather than throwing good money after bad. That way you can forget transmission repairs for a few more decades at least. Your shifty shifts are even more reason just to have it done without too much deliberation. A professional overhaul is cheap. It may often cost as little as less than $2,000 all-up drive-in - drive out, and rarely much more than just $3,000. | ||
| David Gore Moderator Username: david_gore Post Number: 1575 Registered: 4-2003 |
Hi Benoit - +1 for Richard's advice from me. The R-R version of the T400 was modified to allow increased clutch slip to give smoother gear changes expected from a R-R vehicle however this was at the expense of increased clutch plate wear. When I sought advice from a well-known local R-R specialist before overhauling my T400, he mentioned it was not unusual in cars mainly used for stop/start city driving to require clutch plate replacement before the cars had travelled 100,000 miles. As a consequence of this information, I used the modification recommended with the B&M transmission kit to stop the clutch slip; this stopped the slip at the expense of perceptible but not excessively so gear changes except on full-throttle acceleration where the immediate take-up was obvious. In normal driving with judicious use of the accelerator, traditional R-R smoothness was possible by feathering the accelerator when the a gear change was imminent. Information on this and other modifications is in the B&M T400 Overhaul Instruction Manual on the following link: https://drive.google.com/file/d/0Bz2EYc0pOpXkamxQVW0wR095YVk/view?usp=sharing | ||
| Benoit Leus Prolific User Username: benoitleus Post Number: 195 Registered: 6-2009 |
Richard and David, I realize wasn't very clear but I am not planning on overhauling the transmission myself, as that's beyond my technical capabilities. However, the transmission shop I'd like to work with prefers to get the gearbox already out of the car as they don't have that much space. Therefore I wonder if it is a DIY proposition to remove and refit the box myself (especially refitting as the box is pretty heavy). Benoit | ||
| David Gore Moderator Username: david_gore Post Number: 1576 Registered: 4-2003 |
Benoit, If the vehicle is at floor level on stands, I would advise to only attempt removing/replacing the transmission if you are physically fit and have good muscle strength. Even if you have a quality transmission floor jack, manipulating the transmission off and on the guide pins to facilitate removal/replacement requires considerable physical effort. If you have access to a hoist, a high-lift transmission jack and a suitable apprentice to help with getting the transmission aligned on the guide pins; the job is much easier and worth considering. In this case, you need a storage area for your vehicle between its times on the hoist unless the hoist owner has no need to use it between transmission removal and replacement. If you are uncertain about your abilities and equipment, my advice would be to get a professional service centre to remove/replace the transmission despite the additional cost involved. | ||
| Geoff Wootton Grand Master Username: dounraey Post Number: 677 Registered: 5-2012 |
Hi Benoit I guess the problem is if you get a service centre to remove the gearbox, how do you then get your car back home whilst you wait for the gearbox to be overhauled. Then there's the problem of getting the car back there for refitting. I do agree with David's comments however I think I'd have a go at doing it myself. I would invest in a transmission jack and a strong pair of ramps for the front wheels. If I already had a reconditioned transmission (more likely with the later 3 speed box) then that would be an entirely different story. I would just get a local service centre to switch the boxes. I guess a final thought is whether you have "mobile mechanics" in Belgium. I know in the UK there are many. Paying someone with suitable expertise and equipment to remove/replace the box at your house may be an option. Geoff | ||
| David Gore Moderator Username: david_gore Post Number: 1579 Registered: 4-2003 |
Geoff - based on my experience, it is best to have the car level on stands rather than at an angle on ramps. It is hard enough to fight gravity extracting the transmission on the level without the extra assistance of gravity pulling the transmission back on a car that is raised at the front and lower at the back. The transmission jack is intended to work with a level transmission and not one on an incline to maintain balance and minimise the possibility of toppling over and damaging the transmission. Replacing the transmission would be even worse as aligning the transmission to mate properly with the bell housing and slide home is very fiddly. However, it can be done in home workshop as my experience proved but one needs to be aware of the factors I have mentioned. | ||
| Patrick Lockyer. Grand Master Username: pat_lockyer Post Number: 941 Registered: 9-2004 |
Try some wynns additive for softening up the seals and use the car more often to cure the leak. | ||
| Vladimir Ivanovich Kirillov Prolific User Username: soviet Post Number: 235 Registered: 2-2013 |
My fellow travellers above have provided excellent advice though I have almost no faith in additives like Wynns, Forte or the myriad of the other in the bottle fixes. I have one chap here in Australia is prepared to send me his product to use and to pay later if it works. I prefer identifying the leak and fixing what ever caused the leak. Often a worn bearing in the reason a seal leaks though seals like everything else eventually wear out at some time. For me removing and placing the transmission is dead easy but I have done it hundreds of times. This transmission is heavy and I don't know if I would use the Italian method on it because not fun if you overestimate your strength and get into a bit of bother where nobody can hear you scream. Here's the Italian method that was taught to me by an Italian born and trained mechanic by Alfa Romeo. Once all the bell housing bolts are out bar one you have a long extension with socket on the last bolt. You lay under the car that has been raised and is secured on quality stands (check the load rating on the stands) and you never get anyway under the car until you have shaken the car to test it is not going to fall as if it falls on top of you it can kill and maim given the two plus ton of weight. You lay with your legs towards the front of the car, open with each knee cap on the underneath of each side of the bell housing, using one hand you undo the last bolt, a quick jerk backwards and the entire weight on the gearbox is upon you. Definitely remove the drive plate to torque converter bolts or you will be singing songs of doom and loathing. Putting it back requires more skill as you pull the transmission onto the first knee cap struggling like a wounded animal to get the other knee cap under the other side. If you have any doubt about your physical ability to do this then don't do it or at least visit the transmission shop and see if they will let you feel the weight of a similar transmission. I did this in Darwin on a 1974 Fleetwood Cadillac in the middle of the humid season with sweat running into my eye sockets almost blinding me temporarily. The Italian that taught me this trick could remove an Alfa Gearbox in 6 minutes. He was indeed a madman. Alternatively, you can use a common trolley jack to remove and replace the transmission but you have to make up a steel plate to fit into the top of the jack's lifting hole and have holes along the plate where you insert ratchet holding straps to secure the transmission to the jack. Unless you have very high car stands holding the car up you are not going to be able to get the jack and the transmission under the car together. When I use this method I grunt the transmission onto the jack underneath the car under the transmission tunnel. The input that others have said about ramps is dead on - you need the car up but level. The cleanliness of the floor is critical. Hopefully, it will be cement and won't have any little pebbles on it to stop the wheels on the jack when you need them to move. I once worked in third world conditions and removed a Road Ranger gearbox from a old Ford Lousiville truck on a truck gearbox trolley jack. It was madness because with that type of weight if the gearbox slips off the jack it can kill and or maim you. Make sure you drain the gearbox before removal unless you want an auto transmission fluid bath. The few dollars spent on a rear seal transmission plug is well worth the cost. Actually, no I am wrong, my transmission on the Camargue has a flange that is some how secured to the output shaft internally. There is a difference between a Cadillac Turbo 400 trans and a Rolls Royce Turbo 400. You learn something every day, must have been be kind to mechanic's day when that one was designed. One hideous fiddly thing is getting the transmission to radiator coolant pipes off without damaging the pipe nuts. Use or borrow and use a snap-on pipe spanner. The use of an opener spanner will result in the crushing of the pipe nuts and you just don' want to visit the land of replacing them with the pipes. Getting the horrid mongrels back on can also be a headache. Use only your fingers to start the threads and wind them all the way in before tightening them with the pipe spanner. You may need to gently move the pipes to get them on the right angle because you don't want to strip or cross tread them as that is the job of apprentices. Most importantly, stock up the liquor cabinet and warn your better half of a necessary but essential booze fest. Remember working on your Rolls Royce can be an emotional matter. I have seen a surgeon almost led away on a chain to the funny farm when he attempted to do his own car repairs and that was on a Holden. He could cut people up with a scalpel and put them back together but he only tried repairing his car by himself once. A word from my old Tech College teacher "RTBB" (Read the bloody manual) First thing after RTBB disconnect the battery. Enjoy | ||
| Jonas TRACHSEL Frequent User Username: jonas_trachsel Post Number: 62 Registered: 2-2005 |
Benoit Add up the cost for a transmission jack (to be used only once in decades as per Richard's projection) plus some ramps plus the booze and all other sundries involved to do the job at home. I consider it not worth the trouble. I would look for a workshop to get the tranny removed and refitted, where they have some safe storage space for your car while waiting for the tranny to come back. | ||
| Jean-Pierre 'JP' Hilbert Frequent User Username: jphilbert Post Number: 69 Registered: 9-2013 |
Benoit, where abouts in Belgium are you again? I'm in Luxembourg and plan to remove & overhaul my 3-speed gearbox next week as soon as the master overhaul kit arrives. I have substantial leaks to the front and rear, and also a hard 1-2 upshift and a hard 3-2 downshift 8if selected manually for downhill motor brake). @ RT ''It will need a new front seal and to have the torque converter neck either machined, sleeved or replaced. Simply replacing the seal may buy a few months only. '' Richard, I hear this the first time. Can you expand on this, I'm very unsure now. What I planned is to replace all the bushings and before that, measure the present bushings in order to see what gap there is/was. | ||
| Benoit Leus Prolific User Username: benoitleus Post Number: 198 Registered: 6-2009 |
Hi Jean-Pierre, I live close to Antwerp, so quite a distance from Luxembourg. As the leak is not yet that excessive and the box not that bad I will probably do the work in the winter. However, I got a quote for € 2.904 (+/-2.090 Pounds) from my local transmission shop to overhaul the box and an additional € 847 (+/- 610 Pounds) to remove and install it. As Flying Spares sells an reconditioned box and convertor for 1.194 Pounds, I might opt for that and do the swap myself. Benoit Benoit | ||
| Hubert Kelly Prolific User Username: h_kelly Post Number: 171 Registered: 3-2012 |
Type in rollsroycenut into YouTube and you will see Ronnie Shaver from California recondition an entire gm400 box over approx 4 chapters | ||
| Jean-Pierre 'JP' Hilbert Frequent User Username: jphilbert Post Number: 70 Registered: 9-2013 |
Yepp, this is a good one, thanks Hubert, for reminding! Still, I don't quite understand how the internal rubbers in a 40 year old gearbox are not hard and stiff whereas ALL rubbers and EVERYTHING ELSE closely related to rubber is perished on the rest of the car. That's why I prefer to overhaul the complete gearbox and this will provide me with fresh clutch packs and bands too (and hopefully cure my hard 1-2 upshift). There are quid a few good videos on TH400 on YouTube. Simply search for ''TH400''. | ||
| Geoff Wootton Grand Master Username: dounraey Post Number: 687 Registered: 5-2012 |
What a really useful thread this has been. I have completely changed my opinion in light of what has been written. I would not now try to remove a gearbox from under the car. The key is having the right equipment and in my book this means a vehicle lift and transmission jack, both of which I do not have. Also, I'm not sure I would have the strength to lift one of these boxes. Lying underneath the gearbox with the car supported (precariously?) on stands would not be a good way to find out. 800 Euros to remove and replace the box - I'd take that any day. But here's a question. What about removing the engine and gearbox through the bonnet aperture. Is this possible? With the grille and radiator removed, would there be enough clearance to pull the whole lot out with an engine hoist? Geoff | ||
| David Gore Moderator Username: david_gore Post Number: 1584 Registered: 4-2003 |
But here's a question. What about removing the engine and gearbox through the bonnet aperture. Is this possible? With the grille and radiator removed, would there be enough clearance to pull the whole lot out with an engine hoist? Geoff, the simple answer is no. The front sub-frame carries the engine and transmission and this entire assembly can be removed as detailed in TSD2476 Section H1. After reading this section and assessing the equipment and space available, this method might be appropriate for you. I am presuming you have downloaded the high-res version of TSD2476 from the Technical Library. | ||
| Jean-Pierre 'JP' Hilbert Frequent User Username: jphilbert Post Number: 71 Registered: 9-2013 |
We did exactly that last week, removing the engine together with gearbox attached, through the bonnet. However, David is right, the subframe is in the way so we had to unbolt it (4 big and 2 smaller bolts) and lower it somewhat (with springs and steering disconnected of course). N.B. the car was a wreck before we started. The picture shows myself exercising the important function of providing downward force to the gearbox in order to extract the engine. .  |
