• Hey Guest!
    British Car Forum has been supporting enthusiasts for over 25 years by providing a great place to share our love for British cars. You can support our efforts by upgrading your membership for less than the dues of most car clubs. There are some perks with a member upgrade!
    **Upgrade Now**
    (PS: Upgraded members don't see this banner, nor will you see the Google ads that appear on the site.)
Tips
Tips

Tranny Disassembly, TR 4 syncro box

Share this page

Tinkerman

Tinkerman

Darth Vader
Offline
I am moving ahead with the disassembly of the syncro box that the PO bought. Was working on it over the weekend and tried various methods to remove the center main bearing, several of you offered various methods and suggestions all of which I tried without success. I really feel that I was being too gentle on it, I also had visions of cracked case after whomping it too enthusiastically.
This morning I took the case to the largest and only tranny shop in town, told them what I needed and they said they would give me a call. Call came about an hour later with a message that chilled my heart. something like "Mr. LeClair could you come to the shop we need to talk to you about your gear box" or words to that affect. If I had hair on my head it would have been standing straight up.
Got over there and the bearing was out, and the main cluster was out. No problems that I didn't know about, Yea! He told me that he used a split bearing puller and an air hammer to remove it. I knew I was too gentle with it. I asked him what the cost was, he told me and I had to sit down! $0.00. Welcome to small town America! Then he said any more problems let him know! My gaster was flabbered.

Question though, as I looked at all of the goddies in the box I noticed that the first gear syncro ring had 0 teeth. They were all ground dowm (picture attached). All the other syncro rings are OK just this one. What would cause that kind of condition?

As always your thoughts greatly appreciated!

Tinkerman
 

Attachments

  • 12389.jpg
    12389.jpg
    88.7 KB · Views: 195
The crunch you hear with a worn-out syncro is the dog teeth grinding.Yours have reached the next level of shot, where your mechanic starts to giggle and point...
MD(mad dog)
 
Yep I agree MD, not only does he giggle and point but he starts listening to the kaching of the cash register.

My question to folks is what causes the nashig of teeth? Also what would be an allowable wear limit on the counter shaft, as measured with a michrometer?

Thanks, Tinkerman
 
Tinkerman said:
My question to folks is what causes the nashig of teeth?
Click to expand...
A lot of fast down shifting into first would be my guess.


<div class="ubbcode-block"><div class="ubbcode-header">Quote:]
Also what would be an allowable wear limit on the counter shaft, as measured with a michrometer?

Thanks, Tinkerman [/QUOTE]

This is the most common area of failure and high wear. Buy a new shaft and bearings for the counter gear cluster and sleep better at night.
 
I have been considering doing a tranny rebuild myself but am somewhat apprehensive. Is it something that someone with a moderate skill level and a Bentley manual can do? What special tools/skills are needed?
 
Yes I remember the first time I took one apart. I used the Haynes manual as a guide and found it very helpful, and I was a little set back, because if I remember right, it said to set a couple of wrenches on each side of the bearing and pound it out with a BFH . Anyways, and again if I remember right, all the syncro rings have the same part number, but the first gear syncro works the hardest because the gear ratio is not in its favor. For example, fourth gear syncro has it the easiest because the ratio is in its favor because the two gears are roughly the same size, the gear on the counter shaft and the gear on the main shaft ; whereas, in first gear the teeth travel more distance because the gear is bigger.
 
I found this 4 part article very helpful. You may want to study it to help determine whether you want to proceed on your own. It is important that you have the all the right shims (they come in various sizes) to replace the ones that are worn. The Bentley manual is a must.


https://www.tr6web.com/Documents/tr6/Tran1.html
 
Ray, thanks for the link. Its all printed out and ready to go in the binder with the other info.

Tinkerman
 
Back
Top