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Detent Springs

2K views 11 replies 4 participants last post by  Alfaboutvegas 
#1 ·
Does anyone have some information on the 3 detent springs under the top hats as to what the "new' length is supposed to be? One source doesn't mention length and another source says they are longer than what came out.
It would seem that as long at they are not deformed, uniform in length that when installing they should offer some serious resistance

Just trying to reason out what is fact.
 
#3 ·
Uncle Rick, your correct that rarely if ever there is a problem unless they break or are deformed, which I have seen both. As to the lengths, there are two camps. One is like what you said and that applies to the early gearboxes. There is the other camp which say s that the free length is 35.8mm (1.41 in) and under load 17.2 mm (.69 in) as shown on pg 75 of the Intereurope Workship manual 133, for the later gearboxes.

The springs that I have here in front of me are 30mm.

I was just wondering how much of a difference there might be between 35.8 mm and 30mm? They must have been working because all of the used springs I have here are 30mm.

Just trying to sort out if 30mm is acceptable.

Then where do you get new springs if you want to go with 35.8 mm?
 
#7 ·
Depends on the year. There were different height hats over the 105/115 series run.
 
#8 ·
Uncle Rick, I can call John Norman and field the question. Thank you for your responses.

I was surprised that there were two lengths of springs when I first looked into this issue, and then when I measured my springs, it was in between. I will have to delve into my stash and see if I can find some top hats and compare those as well.

There was a change at some point in the securing bracket from two studs to using two bolts. It does take a thin 10mm socket to fit in between the top hats to get either of them out.

In the end, it may not come to anything dramatic, but it is worth asking the question. :)
 
#9 ·
From what I have gleened from the usual manuals the 'hat" and spring sets for 5th/R evolved into something a little more stout by loadiing that spring more. I would bet that accrued over time as REV always was a little more prone to pop out of gear and 5th was just a side bar benefactor of trying to make it a little more beneficial for the REV function without specifying a design change to deepen that particular groove on the shared shift rod. I have to bet that was a footnote and amendment to the later assemblies. There is always a reason for changes to the design over time.
 
#10 ·
Nothing worse than having the trans pop out of rev/5th gear. Yes, most likely it was a factory change without anyone noticing to resolve irritation. My guess would have been with the introduction around the time of the 1750 development. I found a set of new springs and when I get them, I will post a measurement.
 
#11 ·
Seems that my source in print is not correct for 35mm. In asking around to those that have new springs, the resulting answer is 30mm. What I have in front of me are springs that are within tolerance. This is an issue we can put to bed. :)
Thank you to all who participated in the discussion.
 
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